Where are static variables stored (data segment or heap or BSS)?

I got conflicting opinions about the storage of static variables.

Opinion 1: Static variable < retains its value in the heap "

Opinion 2: "Static variable < retains its value in the data segment. "

I am confused by these conflicting answers.

Where are the static variables stored?

I expect answers with links (tutorials, genuine tutorials, etc.).

Static variables have two types:

• static variables declared inside a function.
• global (declared external function) static variable.

I would also like to know if there is a difference in storing these two types of variables?