Google says that “Plugins are actual software programs on our computers that interface with the browser. This includes Flash and Java that have a browser hook so that any web page can get access to the code on your machine.”So plugins are a piece of code. In jQuery plugins it is a code written in a standard JavaScript file. These JavaScript files provide useful jQuery methods that can be used along with jQuery library methods. We have an online jQuery Plugin Registry, you can download plugins from here.After downloading a plugin, let's explain how to use it.We use a plugin file similar to jQuery library file in the <head> of the document. This file is used before our custom JavaScript code and just after the main jQuery source file.ExampleHere in the Red border, we used a plugin. You can read more about the plugins from plugins.jquery.com.You can also develop your own plugin.It is very simple to write your own JavaScript file. Let's understand how to write our own plugin.Syntax