Hash functions and some of their properties, examples, and then one special function SHA-256 used by Bitcoin are discussed in this bachelor’s thesis. It is explained how hash-pointers serve us in building linked lists, or blockchain. It is given a digital signature scheme and the idea of using its random generated public key as identity was elaborated, which we use to understand the mode of decentralization in functioning Bitcoin and privacy. Some primitive cryptocurrencies and some of their properties that will be inherited by Bitcoin are listed, types of transactions and problem of doublespending attack. In third chapter it is explained the concept of decentralization as very important concept of cryptocurrencies and what is distributed consensus. Furthermore, there is an explanation of Bitcoin transaction and necessary conditions which we have to meet if we want to carry it out. There is given the structure of Bitcoin block containing a Merkle tree, which makes it very useful because of easy tracking and verifying transactions. The last chapter is devoted to storing Bitcoin. There is explained the way the wallet software works, the coding of the address for exchanging, and the method of calculating transaction priorities depending on fees for the miners. The possibilities of buying or selling cryptocurrencies, which are the main sources of demand for Bitcoin are briefly explained, and there is a simplified mediation model from which we find the formula of the equilibrium of its price.