Hash

A hash might sound more like a food item which can be bought from a diner in the morning, however, in the concept of blockchain, it is a very crucial feature. A hash is simply a collection of alphabets and numeral digits derived from any item of data by means of a specific technicality known as the cryptographic hash function. The output hash from the algorithms is always of the same size regardless of the size of the data you feed the algorithm. And here’s the cool part: however, modification as minuscule as a single bit will result in an entirely new hash value – it is perfect for determining whether something has been meddled with or not. 

In the constitution of blockchain, hashes are used to interconnect the subsequent blocks. In the block structure of the chain, the block includes the hash of the previous block – and this makes the whole affair pretty secure. As for the last one, if someone attempted to meddle with a block’s data or information, the hash would be different, which breaks the link. This makes it extremely difficult for would-be hackers to tamper with the blockchain because to do so would be detected immediately, which is why people trust it so much.