Is it possible to store data between PostBacks in a non-static class?

Question

Data storage

Good afternoon!
There is a dynamic .aspx page. It is filled in by the user with various data. I want this data to be saved between PostBacks in a non-static class located in a separate .cs file
. For example, a class:

class MyClass
{
  string a;
  string b;
}

Class Enrollment

MyClass my_class = new MyClass();
my_class.a = "значение 1";
my_class.b = "значение 2";

After PostBack, this data is lost. How to make the data stored in the class?
It is assumed that several users from different machines will work at the same time, so static fields cannot be used.

Answer 1

Here is the answer with examples.