What is VOIP?

 ??What is VOIP  

VOIP is an acronym for Voice Over Internet Protocol. The acronym accurately describes the purpose of the technology, yet hints at the difficulties in implementation to those familiar with IP (Internet Protocol). The term VOIP refers to no particular protocol or method, rather, the term applies to a number of technologies that aim to adapt the Internet's packet-based data exchange methods to real-time two-way communication.

Internet Protocol (IP) prioritizes the reliability of data transfer over the speed of data transfer. Thus, if 100 packets are sent in one second, IP makes sure that 100 packets are received, even if it takes 30 seconds to receive them. This type of system ensures that the file received exactly matches the file sent. However, this type of data transfer is not well suited to voice communication. Imagine what a telephone conversation would be like if one second of speech took 30 seconds to hear! The main challenge in creating a usable VOIP protocol is in ensuring that every one second of speech sent is played back on the receiving end in a one second time span, without waiting for all the packets to be received.

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The most popular VOIP protocol in use today is the proprietary Skype protocol. Yahoo, Microsoft, AOL, and countless others have competing VOIP protocols incorporating a variety of creative solutions to the problem. Many of them have near-ISDN quality when used in high-bandwidth environments, yet none of them can cope in a dial-up (56 Kb/s) environment. Also, in some areas VOIP service is being rolled out as an alternative to traditional ISDN lines, with special equipment that ensures compatibility with legacy telephones.

What is Google?

 ???What is Google 

Google.com is a website whos mission is, in its own words, "to organize the world's information and make it universally accessible and useful". It is the largest search engine on the internet, and additionally offers services such as email, maps, news alerts, shopping, calender, blogging tools, and more. According to Alexa.com, Google.com is the third most popular website on the internet.

In the beginning, Google.com differentiated itself from other search engines in the technology used to rank the importance of any particular webpage. While most search engines active during the time of Google.com's launch rated a pages' importance based upon the amount of times a certain keyword appeared on the page, Google.com rated paged based upon the number of other webpages linking to it. Thus, Google.com returned higher quality websites to searchers, and quickly overtook the largest search engines of the time.

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However, Google.com has seen its fair share of controversy. Despite the company's principle of "You can make money without doing evil", may people have accused the service of collecting users' personal information and various privacy exploits. The most famous of these was the Gmail.com advertising criticism. As Gmail.com delivers advertisements based upon the content of a users' email, some people had believed that Google employees were reading users' mail. In fact, the technology behind the system has a computer parsing all displayed mail, and serving relevant advertisements. No Google.com employee has access to Gmail.com users' private information, including preferences, demographics, and mail.

What is Ajax?

 ??What is Ajax

Ajax is an acronym for Asynchronous JavaScript and XML. Ajax is a technique whereby a website can update part of a page without refreshing the whole content. This saves bandwidth and provides for a more interactive user experience. In other words, changes that a user makes appear quicker on the screen, and the website seems to respond much faster. The improved action increases the interactivity of websites and makes the user experience much more enjoyable. It should be noted that Ajax is not a technology in its own right, rather, it is a technique that utilizes other technologies. Ajax is considered one of the core techniques behind Web 2.0 applications.

The main components behind Ajax are XHTML, the DOM model, JavaScript, XML, and CSS. Websites coded in XHTML have very accessible Document Object Models, by definition. JavaScript can be used to interact with the DOM, and to manipulate it. As the JavaScript can also make HTTP requests, it is a convenient bridge for requesting new data from the webserver, and for replacing part of the webpage with the new content. Usually, the new content is transferred in XML, as XML is relatively easy to parse. Finally, CSS is used to define page markup. Note that the webserver in question must be running a programming language capable of serving XML requests to Ajax applications, such as PHP or Perl.

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While the use of Ajax generally makes websurfing more enjoyable for the user, the programmer must be careful not to break accepted website behavior with Ajax. A common problem with Ajax applications is the disability of the web browser's Back button. In a normal non-Ajax application, every webpage has a unique URL. Thus, a user can hit the Back button to take him back to the previous URL, which would be the state that the browser was in before the user's last action. This can be seen as a sort of Undo operation. However, with Ajax the URL of the webpage does not change every time the state of the web application changes. Therefore a press of the back button will bring the user to a state much further back than he might have intended. Also, page bookmarking is dependant upon the URL of the page in question. Therefore, pages created by Ajax will not be bookmarkable. Professional programmers have in fact developed techniques to circumvent these issues, however, they are far from perfect.

What is Teleportation?

 ??What is Teleportation

Teleportation is the transfer of physical objects from one place to another, distant place, without transferring the physical particles that constitute the original object. By most definitions, the object in its original location is either destroyed or rendered otherwise unrecognizable and unable to function. This limits teleportation devices to transportation roles only, incapable of duplicating or manufacturing objects. Although teleportation devices were until recently considered by the scientific community to stay confined to the realm of science fiction, recent understandings of quantum mechanics have led to the development of successful teleportation techniques.

The current state of the art in teleportation technology, having successfully moved relatively large masses relatively large distances, relies on the uncertainty principle and quantum entanglement phenomenon. The uncertainty principle states that the more information that is extracted from an object, the more the object is malformed. The point in which the object is so malformed as to prevent further scanning occurs well before enough information is extracted to produce an exact copy. Quantum entanglement allows the quantum state of one particle to be predicted based upon the quantum state of another particle that had once been in contact with it. Thus, a teleportation sending station and receiving station can be prepared by bringing two such particles into contact, and then bringing one to the sending station, and the other to the receiving station. The particle at the sending station is then scanned along with the object to be teleported. The scanning process malforms both the particle and the object. The scanned information is then sent to the receiving station, which then performs the reverse process to raw material together with the second particle. As the second particle is currently in the same quantum state as the first particle, together with the original object, the finished product is identical to the original object.

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The first objects to be successfully teleported were photons, or light particles. These massless particles are ideal for such experimentation as the have relatively few quantum states and readily entangle with other photons. As early as 1998 experiments have proven with over 75% accuracy that the quantum state of a photon can be imparted on a distant photon by way of an intermediate photon that is quantumly entangled with the target photon. While this method could theoretically be used to transmit data, it would not permit the movement of tangible objects. Six years later, two separate research teams had independently succeeded in teleporting collections of atoms. Although the atoms themselves had been teleported, their respective arrangement had not been preserved. Thus, the current state of the art does not permit the teleportation of large or complex structures. However, new developments in technology, as well as a more thorough understanding of quantum mechanics, may help researchers overcome that obstacle.

What is a Website?

??What is a Website

A website is a collection of webpages hosted under a common domain. Usually, all the pages of a website are stored on the same physical server, have the same basic layout and interface, and are interlinked via hyperlinks. This rather general definition is often excepted, as many popular websites spread their bandwidth load over several servers (google.com, for example), and still other websites are hosted under one general domain name (geocities.com, for example). While there is no formal definition of what is and what isn't a website, any collection of documents on the World Wide Web that are available under a common address and reference each other are considered to be a single website. The term website is often shortened to just "site" in speech, and is written as two separate words "web site" in some strict publications.

The first website open to the public was the CERN site, who's purpose it was to promote the World Wide Web. Indeed, the web server, the web browser, the HTTP protocol, and the HTML markup language were all inventions of a single CERN employee. The original first webpage is still hosted at CERN for historical reasons, albeit at an archived address and not at its original address. All the early websites have a distinctly outline form, which reflects HTML's outline nature. Even today it is considered proper form to code websites in outline form, from the structure of the directories to the semantic structure of the pages.

a Website logo

While the concept of a website and the World Wide Web in general had been designed to facilitate the sharing of information, many websites are coded in such as fashion as to actually hinder their availability and accessibility. Some website-authoring tools, such as Microsoft FrontPage, create websites in non-standard code, rendering them inaccessible to all but proprietary web browsers, such as Microsoft's own Internet Explorer. Often, the webmasters of these websites are uninformed, and as have effectively made it impossible for users of other web browsers to access any complaint vector, have no way of knowing about the problem. This phenomenon had led to a situation where website authorship is no longer a simple procedure that any proficient person could learn, rather, the testing of different browsers under different conditions is something that only a seasoned professional could accomplish.

What is Firefox?

 ??What is Firefox

Firefox is Mozilla Corporation's popular open source web browser. Firefox was originally intended to be a lightweight version of Mozilla's Netscape (Seamonkey) browser, intended for those who need a web browser only and do not need the rest of the software suite. Since its inception, Firefox has become far more popular than Seamonkey and is considered to be the first browser to seriously challenge Internet Explorer's market dominance. Once marketed as an "alternative" web browser, Firefox is now recommended by standards implementations bodies and by web designers alike for use as a primary web browser.

Although the base Firefox installation is quite sparse, Firefox allows the user to expand its functionality with third-party extensions. These extensions include spell checkers, advertisement blockers, navigation tools, and more. While Mozilla hosts an official extensions website, there are many other sources for Firefox extensions. Note that extensions on Mozilla's website are inspected and therefore considered safer to use than extensions found elsewhere.

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Firefox is considered to be much safer to use than Internet Explorer. Also, Firefox lets the user customize the browsers' behavior, thus leaving the user exposed to less "web frustrations" such as popup advertising. Firefox does not use ActiveX controls, so many website exploits will not work on computers running Firefox. However, downloaded files are beyond the browser's control and must be scanned for viruses and other malware, no matter what browser was used to download them.

What is Opera ?

??What is Opera

Opera is an internet suite consisting of a web browser, an email client, a chat client, and a contact manager. The Opera web browser is usually hailed as an innovative and secure web browser, with many popular features of modern web browsers being Opera innovations. Additionally, Opera has a better security record than any other browser for Microsoft, Macintosh, and UNIX-based operating systems. Traditionally, the Opera suite was funded by the user's choice of either paying for the software, or having ads displayed in the browser. Since version 8.50, released in 2005, Opera is free to download and install on any supported operating system. It is not, open source, however, which some people claim is the only barrier preventing it from overtaking Firefox as the leading non-Microsoft web browser.

Many of the newest features of today's web browsers have been present in Opera for years. The tabbed browsing feature of Firefox and IE7 has been present in Opera since 1994, and features such as search aliases, page zoom, sessions, and user-defined stylesheets were introduced in Opera in the mid-1990's. Even Firefox's acclaimed "Clear Private Data" feature has been standard in Opera since version 4 was released in 2000. That same year, Opera released the fifth version of the web browser that shipped with features such as mouse gestures, integrated search, and popup blocking, all standard features on today's browsers.

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Opera's security record is not only the best of any available web browser, it is also better than almost any other software in any category. While vulnerabilities have been found in the web browser, they are usually patched within days of being discovered. This is in contrast to the 23 day exploit-to-patch average for Internet Explorer. Of course Opera, like Firefox, is invulnerable to attacks aimed at ActiveX or other Microsoft-proprietary features. And malicious software cannot automatically download and install itself when a user browses with Opera. That said, Opera may be considered to be less vulnerable to exploits than other web browsers as it is deemed less of a target than more popular web browsers. If more people were to use Opera, some claim, then the writers of malicious software would code specifically for it.