I'm trying to write a "standard" business web site. By "standard", I mean this site runs the usual HTML5, CSS and Javascript for the front-end, a back-end (to process stuff), and runs MySQL for the database. It's a basic CRUD site: the front-end just makes pretty whatever the database has in store; the backend writes to the database whatever the user enters and does some processing. Just like most sites out there.

In creating my Github repositories to begin coding, I've realized I don't understand the distinction between the front-end back-end, and the API. Another way of phrasing my question is: where does the API come into this picture?

I'm going to list some more details and then questions I have - hopefully this gives you guys a better idea of what my actual question is, because I'm so confused that I don't know the specific question to ask.

Some more details:

• I'd like to try the Model-View-Controller pattern. I don't know if this changes the question/answer.
• The API will be RESTful
• I'd like my back-end to use my own API instead of allowing the back-end to cheat and call special queries. I think this style is more consistent.

My questions:

• Does the front-end call the back-end which calls the API? Or does the front-end just call the API instead of calling the back-end?
• Does the back-end just execute an API and the API returns control to the back-end (where the back-end acts as the ultimate controller, delegating tasks)?

Long and detailed answers explaining the role of the API alongside the front-end back-end are encouraged. If the answer depends on the model of programming (models other than the Model-View-Controller pattern), please describe these other ways of thinking of the API. Thanks. I'm very confused.