Introduction to Smart Card Technology:
We live in a world fueled by technology, advancements in this industry have helped us optimize the tasks which normally would consume a lot more time and would be prone to errors. One of these advancements is “smart card technology”. Smart card technology has made payments, financial transactions and online shopping a lot more convenient and secure, and these are but a few benefits. 
What exactly is a “Smart Card”?
A smart card is a basically a tiny rectangular shaped card with an embedded integrated circuit which can process data. A smart card is about the same size as your driver’s license card which you can easily fit into your wallet or back pocket and it is usually made of either metal or plastic.
Now, why do we call them “Smart” Cards?
They are called smart cards because they can bear tiny memory chips embedded in them which act as microprocessors. The microprocessor is located under a gold contact pad on one side of the card. These smart cards can contain up to 8 kilobytes of RAM, 346 kilobytes of ROM, 256 kilo-bytes programmable ROM and a 16-bit microprocessor.
They can thus store information about the owner of the card. This can include private information and data. The user can then use them to carry out financial transactions such as making payments while shopping, paying bills online and transferring funds. Smart cards are made tamper-proof and use data encryption to provide protection.
Now these smart cards can be used for a variety of functions and they can come in many sizes but they essentially follow the same technology which allows users to make payments without having to use physical cash.
Construction of Smart Cards:
A smart card is made through the following four basic steps i.e. designing, fabrication, coding and data loading.
- Designing
The first step involves the designer/programmer who allocates a memory size to the chip being used, specifies the clock speed, the volatile memory type and the OS for the chip. The programmer also must create an application software for the card specifying the card type and any other features required in the card. 
- Chip Fabrication
In this step, the silicon chip is fixed into the card. The chip is linked to connectors via connecting wires by either soldering them together or bounding them. Next, epoxy resin is used to seal the chip onto the board substrate which is then glued to the substrate of the card. The substrate is made of plastic or PVC or any synthetic plastic.
- Chip Coding
In the next step, the chip is coded. The programmer will use special commands to enter codes into the chip.
- Data Loading
In this final step, the user’s data and information are fed into the memory chip.
How these Smart Cards Work
Smart cards contain a memory chip within a contact pad. This contact pad is what makes all these transactions possible. The contact pad comes in contact with an external “card reader” and allows for connection between the card reader and the contact pad.
The smart card reader allows you to insert your card into a slot and enter your security code after which you can carry out any transaction. A Point of Sale (POS) system (or any medium which can fulfill this function) is used to help you make these transactions.
Some smart cards are also available which can function without a smart card reader and are becoming increasingly popular.
Classification of Smart Cards
Smart cards can be classified into two types based on their mechanism of use and their configuration. 
Types of Smart Cards based on Mechanism:
- Contact Smart Card:
This is the most commonly used type. It includes credit cards, ATM cards, and SIM cards. These cards are usually inserted into smart card readers which connect with the contact plate on the card and then allow for the user to perform any transaction. The contact points act as a physical connection for the commands and data to be transmitted.
- Contactless Smart Card
This card does not require the presence of contacts. There are no physical means of connection. The card and the card reader make use of radio frequencies and NFC (Near Field Communication) technology in the form of a wireless connection. The card and the card reader are both equipped with antennas and use radio frequencies to communicate. You simply have to bring the card in close proximity with the card reader to be read.
- Hybrid Smart Cards
Hybrid smart cards are a hybrid of the previous two categories of smart cards. They can function as both contact and contactless smart cards when required. These, however, aren’t commonly found. A hybrid smart card could contain both an embedded chip with contact pads and an RFID-enabled chip for close proximity connection.
Types of Smart Cards Based on Configuration
- Memory Smart Cards
Memory smart cards come with memory chips that can store and read/write data and are used for temporary bases. They are not programmable; rather the data can only be overwritten or modified. Memory smart cards can be either rechargeable or disposable. Rechargeable cards can be updated whereas disposable cards can only be used once and then discarded.
- Microprocessor Smart Cards
Microprocessor smart cards have microprocessors embedded into their chips along with memory chips. These are sort of mini-computers that have larger memory spaces and can hence store larger amounts of data. The processors in the card also use an operating system so you can read/write, rewrite and manipulate data whenever required.