The role of plugins
Under normal circumstances, WordPress developers use functions that involve application logic scattered across theme files and plugins. Some developers even change the core files of WordPress, which is considered a very bad practice. In web applications, we need to be much more organized.
In The role of WordPress themes section, we discussed the purpose of having a theme for web applications. Plugins will be and should be used to provide the main logic and content of your application. The plugins architecture is a powerful way to add or remove features without affecting the core. Also, we have the ability to separate independent modules into their own plugins, making it easier to maintain. On top of this, plugins have the ability to extend other plugins. Since there are over 40,000 free plugins and a large number of premium plugins, sometimes you don't have to develop anything for WordPress applications. You can just use a number of plugins and integrate them properly to build advanced applications.