Founded by the great Elon Musk, created a way to make safe purchases online. Sadly he sold it to start up Tesla and a few other things, it still retains its initial goal.
Instead of giving someone your credit card info, PayPal acts as a middleman, taking the money from you, and giving it to them. So they cant charge more than you anticipated, and only once. If your purchase happens to be a scam through PayPal, your 'Pal, will beat them until they say sorry and give you your money back.