How are backend+RESTful API+Databases related?

Question

Database

Please explain the process of interaction of these terms (Is there any?).
Let's say I want to make a project. I'm laying out a website, creating a mobile application, but only at the interface level. I saw such records that a medium-sized project can use a framework of any language as a core. For example, this is Django. But Android applications are written in Java.
It turns out that if I took Django as the basis of the site, then the mobile application will also have the basis of Django if they are connected via the RESTful API? What role does the server play in this?
The questions are probably very stupid. Please help.
And yes, the last question: what topics / aspects do you need to learn in order to understand this?

Answer 1

How are backend+RESTful API+Databases related?

The simplest example is a browser as a client. And [*any_language*] as a REST server. The server at the same time can interact with the database to generate responses to client requests.

But Android applications are written in Java.

Not only in Java... But, it doesn't matter as such what they are written in on the client.

It turns out that if I took Django as the basis of the site, then the mobile application will also have the basis of Django

On a mobile application, with a probability of 99% there will be a client. What it will be written on does not really matter, but Django in android is very unlikely.

What role does the server play in this?

The role of the server, apparently.

And yes, the last question: what topics / aspects do you need to learn in order to understand this?

Specifically about REST - I gave you the link above. I also recommend that you familiarize yourself with the specification for the HTTP protocol, it is useful as an example for your question and in general.

Answer 2

It turns out that if I took Django as the basis of the site, then the mobile application will also have the basis of Django if they are connected via the RESTful API? What role does the server play in this?

REST - the server doesn't care what client is on the other end of the "wire", the main thing is that the correct requests are sent to it. Those. it doesn't matter what both the client and the server are written in, the interaction between them is important. For example, the server can be written in jung, node, php, at least pluses, and there are two clients: a mobile application in java and a web browser. And all this works great over the http protocol. Smoke the principle of its work, and examples of restful api.