Paypal

PayPal is an e-commerce business allowing payments and money transfers to be made through the Internet. PayPal serves as an electronic alternative to traditional paper methods such as cheques and money orders.
PayPal is a type of person-to-person (P2P) payment service. A P2P payment service allows anyone with an e-mail address to transfer funds electronically to someone else with an e-mail address. The initiator of an electronic funds transfer via PayPal must first register with and fund their PayPal account. A PayPal account can be funded with a check or money order, an electronic debit from a bank account or by a credit card. The recipient of a PayPal transfer can either request a check from PayPal, establish their own PayPal deposit account or request a transfer to their bank account. PayPal is an example of a payment intermediary service that facilitates worldwide e-commerce.
PayPal performs payment processing for online vendors, auction sites, and other commercial users, for which it charges a fee. It sometimes also charges a transaction fee for receiving money (a percentage of the amount sent plus an additional fixed amount). The fees charged depend on the currency used, the payment option used, the country of the sender, the country of the recipient, the amount sent and the recipient's account type. [1] On October 3, 2002, PayPal became a wholly owned subsidiary of eBay.[2] Its corporate headquarters are in San Jose, California, United States at eBay's North First Street satellite office campus. The company also has significant operations in Omaha, Nebraska; Scottsdale, Arizona; and Austin, Texas in the U.S.; India; Dublin, Ireland; and Berlin, Germany, and now also in Tel-Aviv, Israel after PayPal acquired an Israeli startup called FraudSciences [1] for $169 million.[3] As of July 2007, across Europe, PayPal also operates as a Luxembourg-based bank.

credit card

A credit card is part of a system of payments named after the small plastic card issued to users of the system. The issuer of the card grants a line of credit to the consumer (or the user) from which the user can borrow money for payment to a merchant or as a cash advance to the user. A credit card is different from a charge car, which requires the balance to be paid in full each month. In contrast, credit cards allow the consumers to 'revolve' their balance, at the cost of having interest charged. Most credit cards are issued by local banks or credit unions, and are the same shape and size, as specified by the ISO 7810 standard.

Debit card

A debit card (also known as a bank card) is a plastic card which provides an alternative payment method to cash when making purchases. Functionally, It can be called an electronic check, as the funds are withdrawn directly from either the bank account (often referred to as a check card), or from the remaining balance on the card. In some cases, the cards are designed exclusively for use on the Internet, and so there is no physical card.[1][2]
The use of debit cards has become wide-spread in many countries and has overtaken the cheque, and in some instances cash transactions by volume. Like credit cards, debit cards are used widely for telephone and Internet purchases.
Debit cards can also allow for instant withdrawal of cash, acting as the ATM card for withdrawing cash and as a cheque guarantee card. Merchants can also offer "cashback"/"cashout" facilities to customers, where a customer can withdraw cash along with their purchase

What is a Bank

A banker or bank is a financial institution whose primary activity is to act as a payment agent for customers and to borrow and lend money.
The first modern bank was founded in Italy in Genoa in 1406, its name was Banco di San Giorgio (Bank of St. George).
Many other financial activities were added over time. For example banks are important players in financial markets and offer financial services such as investment funds. In some countries such as Germany, banks are the primary owners of industrial corporations while in other countries such as the United States banks are prohibited from owning non-financial companies. In Japan, banks are usually the nexus of cross share holding entity known as zaibatsu. In France "Bancassurance" is highly present, as most banks offer insurance services (and now real estate services) to their clients