RainbowCrack uses time-memory tradeoff algorithm to crack hashes. It differs from brute force hash crackers.
A brute force hash cracker generate all possible plaintexts and compute the corresponding hashes on the fly, then compare the hashes with the hash to be cracked. Once a match is found, the plaintext is found. If all possible plaintexts are tested and no match is found, the plaintext is not found. With this type of hash cracking, all intermediate computation results are discarded.