This chapter expounds the main principles behind blockchain technology alongside various its cutting, Edge applications. We first present the core concepts of the blockchain. Secondly, We discuss a definition put forward by we sketch, Vitalik buterin out the shift toward and we, Hybrid solutions sum up the main features of decentralized crypto, Ledger platforms. Thirdly, We show why the blockchain is a disruptive and but we, Foundational technology expose the potential risks and drawbacks of public distributed ledgers that account for the shift toward hybrid solutions. Finally, We unveil a non, Exhaustive list of important applications, Bearing keeping in consideration the most recent developments.