# What is Blockchain?

A blockchain is basically a very secure database that keeps record of all the transactions recorded inside of it, forever.

A public blockchain is a blockchain that is visible for everyone and works thanks to a network of nodes instead of a centralized server.**Good to know:** an employee directory can be a great way to help new folks get familiar with everyone they're going to be working with.

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Is blockchain and descentralization the same thing?

Not exactly. In order to keep data in a descentralized way we need a single and immutable source of truth visible for everyone. Blockchain technologies allow us to do build descentralized networks.
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### Blockchain Expert Explains One Concept in 5 Levels of Difficulty by [@bwarburg](https://twitter.com/bwarburg)

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Don't trust, verify.

Public blockchain are visible for everyone to see and verify all the transactions.
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### How does a blockchain work? by [@savjee](https://twitter.com/savjee)

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### What are smart contracts? by [@savjee](https://twitter.com/savjee)

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