You are misusing the term "plugin". A plugin is generally a package of code that extends or alters the base functionality of a system - to make actual PHP plugins (which in the PHP world are called extensions) you'd be writing C or C++.
This plugin enables PHP code everywhere in your WordPress instalation.
Using this plugin you can use PHP in:
The plugin also supports different user restrictions and multiple PHP instances.
So feel free to just insert PHP in every part of your WordPress site.
Examples of use:
Advantages of PHP
PHP is, an application can be run on various platforms. The most important advantage of PHP is the developer need not have to worry about the operating system the user is working on. As the PHP code run properly and smoothly on all operating systems. Furthermore, the server-side scripting language or PHP hosting service providers can easily be found.
Ease of use
Any individuals who are new to programming can easily learn to use them within a short duration of time. The syntax for programming in the hypertext preprocessor is quite similar to the C programming language. So the individual who is familiar with C can easily create PHP website scripts.
A very vital side of web development is the speed. Considering the very important fact, some individuals still struggle with the challenge of web data speed. A quick loading website always appreciated by many individuals. Furthermore, individuals typically like quick loading web sites compared to slower loading ones. Folks use PHP because of the important fact that it’s quick.
Open source and Powerful library support
Another advantage to using the PHP hyper text Preprocessor is it’s developed and maintained by a cluster of PHP developers, this help in making a support community, extensive extension library. PHP additionally has immense collection functional modules and a few of the modules available in PHP include Graphics and PDF amongst others.
PHP has been in existence for about twenty-two years. Over this era, many developers have worked on the application to enhance the usage of the application. lots of bugs are discovered over the years and therefore the bugs are fixed quickly by the team of developers. Based on this, the programming language is currently very stable.
Disadvantages of PHP
By the way, the PHP preprocessor hypertext language was created, it’ll be tough to use it to program large applications. Since the programming language isn’t extremely modular, large applications created out of the programming language are tough to keep up. Furthermore, it’s so an excellent language for web site scripting and developing small applications.