How smart contracts work and it's use in block chain technology?

Question

I am a newbie in Blockchain technology and found a word "smart contracts". I have searched about it and the only answer I got is....it is a program, which executes some statement, if certain conditions are met.

But I want to know, how this is is useful in Blockchain technology.

When this program is executed??

Does every node have their unique set of smart contracts??

Data Mining is the process of validating the transaction, then why smart contracts are used ?

Please give me an example where smart contracts are actually executed in Blockchain.

Answer 1

When this program is executed??

Indeed, Smart contracts are executed automatically when specific conditions are met.

For example, a smart contract for a rental property might release a security deposit to the tenant once that have returned the keys and left the property in good condition.

Does every node have their unique set of smart contracts??

No, every node on a blockchain network has a copy of the same smart contract code.

Data Mining is the process of validating the transaction, then why smart contracts are used ?

Smart contracts are used in addition to data mining in blockchain. Smart contracts allow automatic execution of agreements without the need for intermediaries such as lawyers or banks. Miners checks transactions and secure the network, while smart contracts make sure everyone follows the rules