Diagram Showing Differnce Sqlite3 and MySql

To my understanding there is Difference between Sqlite3 and MySql. I understand that Sqlite3 works within a website or PHP engine. and MySql is an external Database. I need someone to create a Simple Diagram of the way each one works and the way each one is connected to the website with a Brief paragraph description for each one and a paragraph describing the difference. Simple project, just need to clear out my head of how each one works and what each one is used for.