Internet terms explain

404 Error

A 404 error is a common website error message that indicates a webpage cannot be found. It may be produced when a user clicks an outdated (or "broken") link or when a URL is typed incorrectly in a Web browser's address field. Some websites display custom 404 error pages, which may look similar to other pages on the site. Other websites simply display the Web server's default error message text, which typically begins with "Not Found." Regardless of the appearance, a 404 error means the server is up and running, but the webpage or path to the webpage is not valid.

So why call it a "404 error" instead of simply a "Missing Webpage Error?" The reason is that 404 is an error code produced by the Web server when it cannot find a webpage. This error code is recognized by
search engines, which helps prevent search engine crawlers from indexing bad URLs. 404 errors can also be read by Web scripts and website monitoring tools, which can help webmasters locate and fix broken links.

Other common Web server codes are 200, which means a webpage has been found, and 301, which indicates a file has moved to a new location. Like 404 errors, these status messages are not seen directly by users, but they are used by search engines and website monitoring software.

ActiveX

ActiveX is a technology introduced by Microsoft in 1996 as part of the OLE framework. It includes a collection of prewritten software components that developers can implement within an application or webpage. This provides a simple way for programmers to add extra functionality to their software or website without needing to write code from scratch.

Software add-ons created with ActiveX are called ActiveX controls. These controls can be implemented in all types of programs, but they are most commonly distributed as small Web applications. For example, a basic ActiveX control might display a clock on a webpage. Advanced ActiveX controls can be used for creating stock tickers, interactive presentations, or even Web-based games.

ActiveX controls are similar to Java applets, but run through the ActiveX framework rather than the Java Runtime Environment (JRE). This means you must have ActiveX installed on your computer in order to view ActiveX controls in your Web browser. Additionally, when loading a custom ActiveX control within a webpage, you may be prompted to install it. If this happens, you should only accept the download if it is from a trusted source.

While ActiveX provide a convenient way for Web developers to add interactive content to their websites, the technology is not supported by all browsers. In fact, ActiveX is only officially supported by Internet Explorer for Windows. Therefore, ActiveX controls are rarely used in today's websites. Instead, most interactive content is published using Flash, JavaScript, or embedded media.

ATM (Asynchronous Transfer Mode)

Stands for "Asynchronous Transfer Mode." Most people know of ATMs as automated teller machines -- those friendly boxes that allow you to withdraw cash from your bank or credit account while charging you a ridiculous surcharge for the service. In the computer world, however, ATM has a different meaning. Asynchronous Transfer Mode is a networking technology that transfers data in packets or cells of a fixed size.

ATM uses 53-byte cells (5 bytes for the address header and 48 bytes for the data). These extremely small cells can be processed through an ATM switch (not an automated teller machine) fast enough to maintain data transfer speeds of over 600 mbps. The technology was designed for the high-speed transmission of all forms of media from basic graphics to full-motion video. Because the cells are so small, ATM equipment can transmit large amounts of data over a single connection while ensuring that no single transmission takes up all the bandwidth. It also allows Internet Service Providers (ISPs) to assign limited bandwidth to each customer. While this may seem like a downside for the customer, it actually improves the efficiency of the ISP's Internet connection, causing the overall speed of the connection to be faster for everybody.