Phishing is an email scam that masquerades as a message from a legitimate source.
These emails look like they came from the appropriate business or person. However, they are scam emails that once you click on the link or whatever they are trying to sell, they can either take over your computer with virus or they now have access to your personal information. Sometimes these emails will say the company name as who sent it but if you check the actual email address it is a combination of random letters/numbers.