What is Fraud?
Fraud is anything intentionally made for gain of the creator.
Phishing is fraud that is via email. People will make fake emails that look like they are from the bank, or your job, and they are often used to try to get personal information. If you reply to this, they might get your personal information.
Lets say you just ordered a new laptop for $600 of a website you have never heard of, and 1-2 weeks later, you hear a knock on your door, and you find a box, you open it up, and you see nothing but a brick. You are a victim of retail fraud. People promise a product, and use "fine print" to find a loophole to rob you of your money.
How to prevent fraud.
Never reply to emails asking for personal information.
Research websites or users selling things!
If it looks too good to be true, it probably is.