Extension's variables: global and scene related questions

How do I...?
1

How do the scene and global variables in extensions work?

Are these variable stored in the scene at which the extension’s functions/objects/behaviors are used? Same question regarding global variables: when do they come to life, when an element of an extension is used? Are they stored globally in the project?

2

They work the same as variables from the main events but only the extension can use them.