Online Computer Dictionary

Definition of digital photography

2008-03-07T22:50:00.001-08:00

In today's world, it seems that almost any topic is open for debate. While I was gathering facts for this digital photography, I was quite surprised to find some of the issues I thought were settled are actually still being openly discussed.

Knowledge can give you a real advantage. To make sure you're fully informed about digital photography, keep reading.

The art and science of producing and manipulating digital photographs -- photographs that are represented as bit maps. Digital photographs can be produced in a number of ways:
# Directly with a digital camera
# By capturing a frame from a video
# By scanning a conventional photograph

Once a photograph is in digital format, you can apply a wide variety of special effects to it with image enhancing software. You can then print the photo out on a normal printer or send it to a developing studio which will print it out on photographic paper.

Although the resolution of digital photos is not nearly as high as photos produced from film, digital photography is ideal when you need instant, low-resolution pictures. It's especially useful for photos that will be displayed on the World Wide Web because Web graphics need to be low resolution anyway so that they can be downloaded quickly.

If you've picked some pointers about digital photography that you can put into action, then by all means, do so. You won't really be able to gain any benefits from your new knowledge if you don't use it.

Wi-Fi Definition Wireless Fidelity

2008-02-15T22:51:00.000-08:00

The following paragraphs summarize the work of Wi-Fi experts who are completely familiar with all the aspects of Wi-Fi. Heed their advice to avoid any Wi-Fi surprises.

The best time to learn about Wi-Fi is before you're in the thick of things. Wise readers will keep reading to earn some valuable Wi-Fi experience while it's still free.

Wi-Fi is the short for wireless fidelity and is meant to be used generically when referring of any type of 802.11 network, whether 802.11b, 802.11a, dual-band, etc. The term is promulgated by the Wi-Fi Alliance.

Any products tested and approved as "Wi-Fi Certified" (a registered trademark) by the Wi-Fi Alliance are certified as interoperable with each other, even if they are from different manufacturers. A user with a "Wi-Fi Certified" product can use any brand of access point with any other brand of client hardware that also is certified. Typically, however, any Wi-Fi product using the same radio frequency (for example, 2.4GHz for 802.11b or 11g, 5GHz for 802.11a) will work with any other, even if not "Wi-Fi Certified."

Formerly, the term "Wi-Fi" was used only in place of the 2.4GHz 802.11b standard, in the same way that "Ethernet" is used in place of IEEE 802.3. The Alliance expanded the generic use of the term in an attempt to stop confusion about wireless LAN interoperability.

There's no doubt that the topic of Wi-Fi can be fascinating. If you still have unanswered questions about Wi-Fi, you may find what you're looking for in the next article.

What is Round Robin DNS?-Definition

2008-02-08T22:15:00.001-08:00

Would you like to find out what those-in-the-know have to say about Round robin DNS? The information in the article below comes straight from well-informed experts with special knowledge about Round robin DNS.

A load balancing technique in which balance power is placed in the DNS server instead of a strictly dedicated machine as other load techniques do.

Round robin works on a rotating basis in that one server IP address is handed out, then moves to the back of the list; the next server IP address is handed out, and then it moves to the end of the list; and so on, depending on the number of servers being used. This works in a looping fashion.

Round robin DNS is usually used for balancing the load of geographically distributed Web servers. For example, a company has one domain name and three identical home pages residing on three servers with three different IP addresses. When one user accesses the home page it will be sent to the first IP address. The second user who accesses the home page will be sent to the next IP address, and the third user will be sent to the third IP address. In each case, once the IP address is given out, it goes to the end of the list. The fourth user, therefore, will be sent to the first IP address, and so forth.

Although very easy to implement, round robin DNS has important drawbacks, such as those inherited from the DNS hierarchy itself and TTL times, which causes undesired address caching to be very difficult to manage. Moreover, its simplicity makes that remote servers that go unpredictably down inconsistent in the DNS tables. However, this technique, together with other load balancing and clustering methods, can produce good solutions for some situations.

Now you can be a confident expert on Round robin DNS. OK, maybe not an expert. But you should have something to bring to the table next time you join a discussion on Round robin DNS.

SaaS Definition from Webopedia

2008-02-05T10:24:00.000-08:00

What is SaaS?
Short for Software as a Service, SaaS is a software delivery method that provides access to software and its functions remotely as a Web-based service. SaaS allows organizations to access business functionality at a cost typically less than paying for licensed applications since SaaS pricing is based on a monthly fee. Also, because the software is hosted remotely, users don't need to invest in additional hardware. SaaS removes the need for organizations to handle the installation, set-up and often daily upkeep and maintenance. Software as a Service may also be referred to as simply hosted applications.

What is Feed?

2008-01-30T21:55:00.001-08:00

A Feed is a Web document that is a shortened version of a Web page that has been created for syndication. Feeds usually end in .xml or .rss.

What is DNS parking?

2008-01-26T05:18:00.000-08:00

What is DNS parking? DNS means Domains Name Server.In the Web hosting business, DNS parking is a service that the Web host will offer to its clients as a way of securing a domain name for future use. The Web host registers the domain name with the InterNIC and "parks" the domain name on a server until it is ready to be made active. By doing this, the Web host ensures the availability of the domain name for the client's future use so that another individual or company cannot register that same domain name.

SERP Definition

2008-01-18T04:10:00.001-08:00

SERP is short for search engine results page, the Web page that a search engine returns with the results of its search. The major search engines typically display three kinds of listings on their SERPs. Listings that have been indexed by the search engine’s spider, listings that have been indexed into the search engine’s directory by a human, and listings that are paid to be listed by the search engine

Reciprocal linking-definition

2008-01-18T04:00:00.000-08:00

A reciprocal link is an agreement between two webmasters to provide a hyperlink within their own website to each other's web site. Generally this is done to provide readers with quick access to related sites, or to show a partnership between two sites. Reciprocal links can also help to increase traffic to your web site in two ways. First you will probably have some viewers visit your site from clicking the reciprocal link directly. Secondly, most Internet search engines also take into account the number of web sites which contain links to your web site; the more hyperlinks to your site found, the higher up in the search engine rankings (depending on the search term) you'll find your site.

CNAME Record definition

2008-01-12T07:13:00.000-08:00

Short for canonical name, also referred to as a CNAME record, a record in a DNS database that indicates the true, or canonical, host name of a computer that its aliases are associated with. A computer hosting a Web site must have an IP address in order to be connected to the World Wide Web. The DNS resolves the computer’s domain name to its IP address, but sometimes more than one domain name resolves to the same IP address, and this is where the CNAME is useful. A machine can have an unlimited number of CNAME aliases, but a separate CNAME record must be in the database for each alias.

Definition of chicklet

2008-01-12T07:11:00.000-08:00

A feed button that normally contains a feed reader logo and has a specific blog or feed information attached to it. It is coded to easily allow users to subscribe to a feed. This is called chicklet.

CTR - Definition

2008-01-06T06:17:00.001-08:00

Short for click-through rate(CTR), the ratio of the number of times a user clicks on an online advertisement per number of viewers who view the Web site that has the advertisement on it. For example, if one out of 100 people who visit a specific Web site click on an advertisement and are taken to the advertiser's site, then the CTR of that advertisement is 1/100, or 1%.

Page impressions- definition

2008-01-06T06:15:00.000-08:00

An advertisement's appearance on an accessed Web page. For example, if the page you're on shows three ads, that's three impressions. Advertisers use impressions to measure the number of views their ads receive, and publishers often sell ad space according to impressions. (It can be tough to know, though, whether an impression really means a visitor saw the ad, since they could be browsing without graphics or might not have scrolled down far enough.) Impressions are tracked in a log maintained by a site server and are often sold on a cost per thousand (CPM) basis.Roman M for representing thousand.

hypertext - definition

2008-01-06T06:12:00.000-08:00

A special type of database system, invented by Ted Nelson in the 1960s, in which objects (text, pictures, music, programs, and so on) can be creatively linked to each other. When you select an object, you can see all the other objects that are linked to it. You can move from one object to another even though they might have very different forms. For example, while reading a document about Mozart, you might click on the phrase Violin Concerto in A Major, which could display the written score or perhaps even invoke a recording of the concerto. Clicking on the name Mozart might cause various illustrations of Mozart to appear on the screen. The icons that you select to view associated objects are called Hypertext links or buttons.

Hypertext systems are particularly useful for organizing and browsing through large databases that consist of disparate types of information. There are several Hypertext systems available for Apple Macintosh computers and PCs that enable you to develop your own databases. Such systems are often called authoring systems . HyperCard software from Apple Computer is the most famous.

January 1, TCP/IP - Video

2008-01-01T01:17:00.000-08:00

Tags: Jan 1 TCP/IP,january 1 2008, january 1, new year, 2008, tcp/ip ,Google, Google Logo, january 1 tcp/ip + video, TCP IP

Abbreviation of Transmission Control Protocol, and pronounced as separate letters. TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent. TCP/IP is the basis of almost all Internet communication, and it was adopted by ARPANET on January 1 (if you don't know, ARPANET was the major foundation to the Internet).

January 1, 83 TCP/IP

This article gives a more in-depth look at what TCP/IP is. It was established as an ARPANET standard on January 1, 1983.

TCP/IP:

IP - is responsible for moving packet of data from node to node. IP forwards
each packet based on a four byte destination address (the IP number). The
Internet authorities assign ranges of numbers to different organizations.
The organizations assign groups of their numbers to departments. IP operates
on gateway machines that move data from department to organization to region
and then around the world.
TCP - is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.
Sockets
- is a name given to the package of subroutines that provide access to TCP/IP on
most systems.

(Yale.edu)

There are many layers built on top of TCP/IP. And another protocol called UDP, which is predominantly used in games and other networking situations where low-latency is required is completely different.

The major layers on top of TCP/IP are:

HTTP: Hyper Text Transfer Protocol (for requesting webpages)

FTP: File Transfer Protocol (for uploading files to websites)

SMTP and POP3: For sending (SMTP) and receiving (POP3) e-mail

IRC: For chatting online

There are also many-non standard protocols built on top of TCP/IP. For instance, AOL Instant Messenger uses a third-party protocol to transfer chat messages between clients!

Spider

2007-12-26T10:41:00.001-08:00

A program that automatically fetches Web pages. Spiders are used to feed pages to search engines. It's called a spider because it crawls over the Web. Another term for these programs is webcrawler.

Because most Web pages contain links to other pages, a spider can start almost anywhere. As soon as it sees a link to another page, it goes off and fetches it. Large search engines, like Alta Vista, have many spiders working in parallel.

Splog

2007-12-26T10:39:00.001-08:00

Short for spam blog, it's a slang term used to describe blogs that are established only to promote affiliate Web sites in order to help those sites achieve a better search engine page ranking.

Podcasting

2007-12-26T10:38:00.001-08:00

Podcasting is similar in nature to RSS, which allows subscribers to subscribe to a set of feeds to view syndicated Web site content. With podcasting however, you have a set of subscriptions that are checked regularly for updates and instead of reading the feeds on your computer screen, you listen to the new content on on your iPod (or like device).

The format used for podcasting is RSS 2.0 with enclosures. The podcasting enclosures refer to all binary (non-text) downloads. You can read the text description of the enclosure before downloading the item to view.

Bookmark

2007-12-24T22:33:00.000-08:00

(v) To mark a document or a specific place in a document for later retrieval. Nearly all Web browsers support a bookmarking feature that lets you save the address (URL) of a Web page so that you can easily re-visit the page at a later time.

(n) A marker or address that identifies a document or a specific place in a document.

AJAX

2007-12-24T22:31:00.000-08:00

Short for Asynchronous JavaScript and XML, it is a term that describes a new approach to using a number of existing technologies together, including the following: HTML or XHTML, Cascading Style Sheets, JavaScript, the Document Object Model, XML, XSLT, and the XMLHttpRequest object. When these technologies are combined in the Ajax model, Web applications are able to make quick, incremental updates to the user interface without reloading the entire browser page. [Source: mozilla developer center]

ATOM

2007-12-24T22:24:00.000-08:00

Atom is the name of an XML-based Web content and metadata syndication format, and an application-level protocol for publishing and editing Web resources belonging to periodically updated Web sites. All Atom feeds must be well-formed XML documents, and are identified with the application/atom+xml media type. [Source: AtomEnabled]

Whois

2007-12-24T11:32:00.000-08:00

An Internet utility that returns information about a domain name or IP address. For example, if you enter a domain name such as microsoft.com, whois will return the name and address of the domain's owner (in this case, Microsoft Corporation).

Keyword Stuffing

2007-12-24T11:31:00.000-08:00

A SEO technique used by Web designers to overload keywords onto a Web page so that search engines will read the page as being relevant in a Web search. Because search engines scan Web pages for the words that are entered into the search criteria by the user, the more times a keyword appears on the Web page the more relevancy the search engine will assign to the page in the search results (this is only one way that search engines determine relevancy, however.) Search engines often penalize a site if the engine discovers keyword stuffing, as this practice is considered poor netiquette, and some search engines will even ban the offending Web pages from their search results.

There are several methods of keyword stuffing. One way is to insert repeating keywords within the input type="hidden" field meta tag or the keyword tag so that the keywords are not seen by the user but are scanned by the search engine. Another way is to make text in the body of the Web page invisible text, or hidden text, by making the text the same color as the page’s background, rendering the text invisible to the user unless the user highlights the text. This method is called invisible keyword stuffing or .

Keyword stuffing also is referred to as keyword loading and spamdexing.

FTP

2007-12-24T10:49:00.001-08:00

Short for File Transfer Protocol, the protocol for exchanging files over the Internet. FTP works in the same way as HTTP for transferring Web pages from a server to a user's browser and SMTP for transferring electronic mail across the Internet in that, like these technologies, FTP uses the Internet's TCP/IP protocols to enable data transfer.

FTP is most commonly used to download a file from a server using the Internet or to upload a file to a server (e.g., uploading a Web page file to a server).

IP Address

2007-12-24T10:47:00.001-08:00

An identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.

Within an isolated network, you can assign IP addresses at random as long as each one is unique. However, connecting a private network to the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates.

The four numbers in an IP address are used in different ways to identify a particular network and a host on that network. Four regional Internet registries -- ARIN, RIPE NCC, LACNIC and APNIC -- assign Internet addresses from the following three classes.

Class A - supports 16 million hosts on each of 126 networks

Class B - supports 65,000 hosts on each of 16,000 networks

Class C - supports 254 hosts on each of 2 million networks

The number of unassigned Internet addresses is running out, so a new classless scheme called CIDR is gradually replacing the system based on classes A, B, and C and is tied to adoption of IPv6.

Also see Understanding IP Addressing in the Did You Know . . .? section of Webopedia.

Google Sitemaps

2007-12-24T10:45:00.000-08:00

Google Sitemaps is an experiment in Web crawling by using Sitemaps to inform and direct Google search crawlers. Webmasters can place a Sitemap-formatted file on their Web server which enables Google crawlers to find out what pages are present and which have recently changed, and to crawl your site accordingly. Google Sitemaps is intended for all web site owners, from those with a single web page to companies with millions of ever-changing pages.
[Source: Adapted from Google Sitemaps FAQ]

DNS

2007-12-24T10:31:00.001-08:00

(1) Short for Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.

The DNS system is, in fact, its own network. If one DNS server doesn't know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.

(2) Short for digital nervous system, a term coined by Bill Gates to describe a network of personal computers that make it easier to obtain and understand information.