RIPEMD160 belongs to the RIPEMD family of cryptographic hash functions developed on the finals of the 1990's in Europe. There exist some versions of 128, 256 and 320 bits of this algorithm, although the most famous one is the 160 bit version.

As can be derived by the name, RIPEMD160 maps input into 160 bits. Usually the most common way choosen to represent those 128 bits is using hexadecimal notation, that is, grouping the bits in groups of 4 bits, which ends up being a string of 40 characters.

RIPEMD160 is a critpographical hash function and thus it can serve multiple purpouses like saving hashes of passwords and saving them to a database, preventing data tempering of files and verifying data integrity over a transaction.