What is junk mail ? Why do we use it ?
Junk mail (mostly in email) is mail that isn't important, has ads, of fake "gifts". We don't really "use" it but sometimes our important mail get's in the Junk Mail file and so we just use it in case it went into a different file
Junk mail in email is where we store all the unimportant mails or mails we don't want. Some email websites delete your junk mail after some days.