What Are Applets?

An applet is a small program that can be run through a website.

Applets are small programs that are built to be run from inside another program. Applets are commonly used by websites to accomplish a task that is complex or impossible to perform in the webpage programming languages. A practical applet would be an embedded video player on a website. An applet works within a larger program like a web browser to perform a task, which makes it relatively useless on its own.

Creating Applets

Applets are typically created through a compiler. Websites are programmed using languages or codes like HTML, JavaScript and PHP, that are specifically designed to display an interactive page and support the infrastructure needed to build it. While these languages are very capable of designing and displaying webpages, there are many programming functions that a website designer may want to incorporate into a site that the web-design languages do not support. Applets are not restricted to the same languages as a website and can be built with languages like Java and Flash.

Using Applets

Applets can be activated through a web browser simply by programming the web page to access or "call" the applet. This practice is very helpful for web designers to add features like video players, chat rooms, and games to a page they are working on without having to know how to program those applets. For example, say Susan programs an excellent video player for her web page. Bob, Tom and Ashley all think Susan's video player is better than the ones they have programmed and ask her to share the player. Bob, Tom, and Ashley can program their web pages to call Susan's video player to play videos on their sites as well.

Uses for Applets

Applets can be used to complete almost any imaginable tasks through another program. An applet that converts a text file to a webpage can be used by multiple editing programs without being rewritten. Applets are commonly used for tasks like converting files from one format to another, collecting and sorting images, playing videos, editing images and performing calculations, all within another program.

Relationship With "Apps" and "Programs"

The computer program or application hierarchy starts with "programs" being full-featured computer code that can be run to accomplish a wide-variety of self-inclusive tasks. An "app" is smaller than a program in that it is used to accomplish a specific task or tasks while still being self-inclusive. An "applet" is similar to an "app" that can be used through a "program" like a "program within a program."

References

• Oracle: About Java Applets
• W3: About Applets