Shannon, PayPal started to allow people an easy method to pay for items purchased at Ebay.
Now it is used world wide to send and receive payments. It is very simple and pretty secure - I am sure that people who have had problems will disagree with the "secure" part - but I have been sending and receiving payments since 2005 and have been well satisfied.
Once you finish the process of signing up for PayPal, your email or phone number becomes your PayPal address. People can send you $$, Invoices for products you have purchased and/or you can make payments directly to a vendor. You can even use your credit card to pay items. Payments can also be reversed if you overpay for change your mind.
All you do is follow the very simple instructions -- I'm going to pm you for your email address..... and send you a small payment so you can see how it works and you can send it back for practice