How does App Engine work?

Question

Google Cloud Platform

Good afternoon!

I worked a little with a virtual machine on Google Cloud - everything is clear here. Just a remote computer in fact.

I don't quite understand the purpose of App Engine. The virtual machine seems to be unnecessary. As I understand it now, just a higher-level hosting is used than in a virtual machine.

Questions:
1) I read this:

App Engine allows developers to build scalable applications in Python and Java without thinking about low-level architecture.

those. the whole point is that we use some containers (as in docker)? In addition to the ease of scaling, there are no pluses?

2) Why language restrictions? And when we talk about the Python and Java languages, do they mean only the back-end of the application?

3) What replaces the virtual machine? Container? And how is work between containers being established?

Answer 1

1. The point is that you don’t have to think about what OS your application is running on, how to restart it, you don’t need to learn kuber and docker.
Just uploaded the code and it already works great and scales.
2. Well, Google has mastered only a python with Java, that's all.

And when we talk about the Python and Java languages, this only means the back-end of the application.

Well, frontend or desktop applications really can't be done, and I don't know how it should work.
I'm not sure what App Engine is, but in Lambda and Azure Functions you can run code, for example, on a schedule - not necessarily exactly the http backend.
3. Cloud serverless magic.
And how is work between instances of a regular, non-AppEngine application being established?

Answer 2

At the level of abstraction where GAE works, there are no containers. Google provides a platform on which to run applications and doesn't care how it works under the hood. This is the advantage, you can only think about the code and not be distracted by the infrastructure.