(i) Electronic wallets (e-wallets) or electronic purses allow users to make electronic transactions quickly and securely over the Internet through smartphones (or) computers.
(ii) The electronic wallet functions almost the same as a physical wallet in term that it holds our money
(iii) Electronic wallets were first recognized as a method for storing money in electronic form, and became popular because It provides a convenient way for online shopping.

Based on the algorithm used, it is classified into the following categories.
(i) Hash chain based micro electronic payment systems.
(ii) Hash collisions and hash sequences based micro electronic payment systems.
(iii) Shared secrete keys based micro electronic payment systems.
(iv) Probability based micro electronic payment systems.

The term electronic payment refers to a payment made from one bank account to another bank account using electronic methods forgoing the direct intervention of bank employees.

1. The cryptocurrency units are created by the solution of cryptographic tasks called mining.
2. The miners not only generate new monetary units, but also initiate new transactions to the block chain.
3. As a reward, they will receive new Bitcoins. In terms of trade, the creation of cryptocurrencies may be related to the ICO (Initial Coin Offer) procedure, i.e. the ICO, aimed at gathering the initial capital necessary for the further development of the system.
4. The initial value of cryptographic currency is just the cost of consumed electricity. The secondary value is determined by the demand for the cryptocurrency.

Stored value card is a type of debit card that is pre-loaded with certain amount(value), with which a payment is made. It is a card that has default monetary value onto it. The card may be disposed when the value is used, or recharged to use it again. The major advantage of stored value card is that customers don't need to have a bank account to get prepaid cards. There are two varieties for stored value card.
(i) Closed loop (single purpose) Eg: Chennai metro rail travel card.
(ii) Open loop (multipurpose) Eg.: Visa gift cards.

All Payment cards (including debit card) are usually plastic cards of size 85.60 mm width x 53.98 mm height, rounded corners with a radius of 2.88 mm to 3.48 mm and thickness of 0.76 mm. These standards dimensions are maintained universally in accordance with ISO/IEC 7810#ID-1.
(i) Publisher
(ii) Credit card number
(iii) Name of the card holder
(iv) EMV chip
(v) RFID symbol
(vi) Expiration month and year
(vii) Card brand logo
(viii) Magnetic stripe
(ix) Hologram
(x) Signature
(xi) CVC/CVV

1. A cryptocurrency is a unique virtual (digital) asset designed to work as a medium of exchange using cryptographic algorithm.
2. This algorithm secures the transactions by recording it in blockchain and controls the creation of additional units of the currency.
3. Cryptocurrency is also called as cryptocoins, e-cash, alternative currencies or virtual currencies and are classified as a subset of digital currencies.
4. The function of cryptocurrency is based on technologies such as Mining, Blockchain, Directed Acyclic Graph, Distributed register (ledger), etc. The information about the transaction is usually not encrypted and is available in clear text.
5. The term "cryptocurrency" began to be used after the appearance of the Bitcoin. Bitcoin is the most popular and the first decentralized cryptocurrency. Bitcoin payment system, was developed in 2009 by an unknown person or a group under the pseudonym "SatosiNakamoto".
6. Currently, more than 1300 cryptocurrencies are listed over 200 special cryptocurrency stock exchanges. Most (not all) are based on different types of blockchain technology.
7. Many cryptocurrencies operate on the basis of the same source code, in which the authors make only a few minor changes in parameters like time, date, distribution of blocks, number of coins, etc. These currencies are called as fork. In fork, both cryptocurrencies can share a common transaction history in blockchain until the split.
8. Altcoins is the collective name for all cryptocurrencies that appeared after Bitcoin. The early Altcoins, Litecoin and Namecoin appeared in 2011. Their miners sought to overcome a number of problems inherent in Bitcoin (for example, Litecoin has a higher transaction rate) or use blockchain technology in other areas
9. Many altcoins are inherently very similar to Bitcoin in characteristics and structure.
10. The cryptocurrency units are created by the solution of cryptographic tasks called mining.
11. Blockchains are an open distributed book that records transactions of cryptocurrencies between any two parties in an efficient and verifiable manner.

Credit card is an electronic payment system normally used for retail transactions. A credit card enables the bearer to buy goods or services from a vendor, based on the cardholder's promise to the card issuer to payback the value later with an agreed interest. Every credit card account has a purchased limit set by the issuing bank or the firm. A credit card is different from a debit card where the credit card issuer lends money to customer instead of deducting it from customer's bank account instantly.
Key players in operations of credit card:
Bearer: The holder of the credit card account who is responsible for payment of invoices in full (transactor) or a portion of the balance (revolver) the rest accrues interest and carried forward.
Merchant: Storekeeper or vendor who sell or providing service, receiving payment made by its customers through the credit card.
Acquirer: Merchant's bank that is responsible for receiving payment on behalf of merchant send authorization requests to the issuing bank through the appropriate channels.
Credit Card Network: It acts as the intermediate between the banks. The Company responsible for communicating the transaction between the acquirer and the credit card issuer. These entities operate the networks that process credit card payments worldwide and levy interchange fees.
E.g. Visa, MasterCard, Rupay
Issuer: Bearer's bank, that issue the credit card, set limit of purchases, decides the approval of transactions, issues invoices for payments, charges the holders in case of default and offer card- linked products such as insurance, additional cards and rewards plan.
Advantages of credit card:
1. Most credit cards are accepted worldwide.
2. It is not necessary to pay physical money at the time of purchase. The customer gets an extra period to pay the purchase.
3. Depending on the card, there is no need to pay annuity.
4. Allows purchases over the Internet in installments.
5. Some issuers allows "round up" the purchase price and pay the difference in cash to make the transactions easy.