PayPal in an internet service that allows users to send and receive money over the internet. It is a secure website. Members have a monthly record of all their money paid and received via Paypal and, of course, it can be used for purchases on Ebay. Setting up an account is free and there are no fees charged to the person making a purchase.
It is good for small businesses because it eliminates the need for bank merchant accounts which can be costly. Paypal's fees to merchants are quite reasonable.
Like any internet service, PayPal occasionally can have technical problems and down time which can be frustrating if you happen to be trying to make a purchase just at that time. But they are very security conscious, which is the biggest concern for users.