Hashing involves passing of data through a one-way function that creates a unique “imprint” of the input (hash). In case of even the slightest modification of the input, the imprint will be completely different. This means that the original imprint cannot be undone without extensive calculations and resources. Since blocks are chained together, there is no way anyone can modify an old record without invalidating subsequent blocks. This structure is one of the components ensuring the security of the blockchain.
In general, the more difficult the input is to find, the more secure the hashing algorithm is.
The input transformation always consists of a simplified, condensed output (hash). Such a technique eliminates the need to store and “remember” large amounts of data.
Outside of cryptocurrency, hashing is used to search databases, analyze large files, and manage data. Cryptographic hashing functions are widely used in information security applications such as message authentication and digital fingerprinting. They are an essential part of the bitcoin mining process and play a role in generating new addresses and keys.
The real strength of hashing becomes evident when working with huge amounts of information.
Sources: coinmarketcap.com, coindesk.com, wiki, pixabay.com, oKrypte.sk