The fast, secure way to send and receive money.
For businesses, it is a system you can use to get paid electronically, in a number of different currencies, without waiting for cheques to arrive and clear.
For customers, it's a faster, safer and more convenient way to pay for goods – because they don't have to re-enter financial information every time they buy. They pay from their PayPal account (which is free for them to set up) which PayPal then 'refills' by drawing on their credit card, debit card or bank account. In this way the customer can pay quickly and easily without disclosing financial information.
Customers find it easy to pay, you find it easy to take payment. No wonder people prefer using PayPal.