What is a runtime class in Java in plain language?

Question

Java

Read about JRE and runtime. And I only realized that the runtime class is a subclass of the Object class. You can explain everything in full or throw off the article.

Answer 1

no.
There is an Object which is an instance of a class. There may be many or one.
And runtime is not from this area at all, but from the area of ​​runtime vs compile.
During the project build, you can have a bunch of extra things, like automated tests, which can also be made up of objects. In production, objects for tests are not needed, therefore, runtime classes are allocated that fall into the final distribution, and non-runtime classes do not get there and exist only at the time of compilation / testing.