Spam/Junk Mail
What is it?
Spam is irrelevant messages sent on the internet towards a group of people.
An example is if you get an email that says something like "You have won a free I-pad! Click here to receive it."
How to prevent getting Spam.
To prevent getting spam you can do a few things. You can put a filter on your email. You can block the sender. Or you can get a new email just for signing up for stuff. You DO NOT want to reply to the emails.
Summary
Spam is irrelevant emails messages on the internet toward a group of people. Avoid replying to emails you do not know or need.