Plugins enable us to modify system functionality without the need to alter existing code. For example, plugins can be used to alter content before it is displayed, extend search functionality, or implement a custom authentication mechanism.
In first step you have to create a sand box means creat an xml manifest file which contain all information of your plugin.
And then you write a php file which contain your business logic but you have to follow the strict naming conventions. Your plugin (php file) name all letters should be in small letter.
And there is also a way to directly create plugins from data base because there is also a table of plugin
Basic idea is that when we install plugin in xml file there is information which is stored in table during instalation
that is my xml file
and you see in database all xml information is stored in database
And Now you can create plugin using Insert Query
