"I don't clearly understand ... what 'scope' is?"

Well, the word "scope" could mean many things depending on the context - more details required!

Is this a 'C' language question; ie, are you unsure about the meaning of the "scope" of a 'C' identifier? (eg, the "scope" of a variable)
If so, it might be easier to re-post it as a new thread - as it's not a debugger issue and, otherwise, all the the answers to your many questions are going to get terribly muddled in a single thread!