How does blockchain work in crypto-currencies?

I need help in understanding the concept of blockchain.

Blockchain is the technology that enables the existence of cryptocurrency (among other things). ... A cryptocurrency is a medium of exchange, such as the US dollar, but is digital and uses encryption techniques to control the creation of monetary units and to verify the transfer of funds.

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One of the most important things you will need before using any kind of Bitcoin mining software is a wallet. ... Ledger Nano S Secure Bitcoin hardware wallet for all platforms. Electrum Simple Bitcoin wallet that works on Mac, Windows, and Linux. Samourai Wallet The most popular Bitcoin wallet on Android.

Blockchain is a technology by which people can create useful software and systems.Crypto Currencies are one of the useful things created through block chain

A transaction is a transfer of value between Bitcoin wallets that gets included in the block chain. Bitcoin wallets keep a secret piece of data called a private key or seed, which is used to sign transactions, providing a mathematical proof that they have come from the owner of the wallet