Ok, thank you TrailRider, and Sorry, Marco, I didn't realize there were links to the concepts I don't understand.

Thank you for your answers. I have just re-edited a question to test this, but it does not appear in recent questions.

I don't understand this "will eventually make the question a Community Wiki and you'll no longer gain reputation on that question" and this "you have the ability to add a bounty to a question" and this:"this adds the question to a list of featured questions which users browse and answer frequently". But the problem with adding details, even when I find them very important, is that very often someone comes with the scissors, edits my question and converts it into his question.