PHISHING
You may have also heard of "phishing." It's where you get an email asking you to click on a link to a website but there is no real website there. Rather, hackers use these links to gather information from your computer, compromising your safety. If you don't recognize the sender of the email, delete it. Also, when messages come from legit companies, it's safer to go directly to their website rather than click on the link in the email.
For example, I received an email from "eBay" asking me to fill out a form with my user name, password, and credit card information or they were going to delete my account within 48 hours. What a joke! I forwarded the email to eBay's spoof email division. the email looked legit...it had all the right logos and trademarks, copyrights, etc. However, any legit company will NEVER ask you to verify account information through email!!