WHAT IS A SMART CONTRACT

Smart contract is the most important term when it to comes the world of blockchain and cryptocurrency. So today i am going to tell you about smart contracts in BRIEF and i hope after reading this you will get an overview of smart contracts.

Smart contracts are bascially the building blocks that you use in order to create Dapps(Decentralized Applications). Now to understand smart contracts lets first understand how accounts work. Lets say you have an BITCOIN blockchain account and in that account you can store balance (also you can say bitcoins(BTC)),you have a public address which is used to receive bitcoins and you have a private key of that account by which you can acess your account and manage your balance and do all that stuff . But in case of smart contracts, they have address,they can store balance but instead of having private key they are completely controlled by code which is written in them when they were created. And the code is immutable, which means you can never temper with that code. You can simply say smart contract is an account which is completely controlled by CODE rather than the account which is controlled by user.
And once the smart contract has been written then it cannot not be altered at any value. There is no adminstrator who come in and change the code.

In other words, you can also say a smart contract is an agreement between two bodies in the form of computer code. And smart contracts run on the blockchain and are stored in the public database , so they cannot be changed.
As smart contracts is the agreement in between two bodies, so there is no need to trust on any other third party. And the smart contract will get executed when certain conditions met.
Let me give you an example, i imagine you all know about vending machine which provides items such as beer, snacks etc. after money is inserted into that machine. In a similar way, in smart contracts when someone send some balance (say ether) and certain conditions satisfied which is written in that code then smart contract get executed and perform the specific task.

There are many applications of smart contracts in diffrent fields like insurance,legal proccess,financial trades,ICO's ,health systems and much more.
There are many public blockchains on which you can build smart contracts like etherium,neo etc. But the most popular one is Etherium and this was the first public blockchain which introduces smart contracts.
Now, i hope you get an idea what a smart contract is. And please do comment if i am somewhere wrong. I'll be very happy to read your comments and your thoughts and would love to have your suggestions.