TLSv1.2 is a revision to the TLSv1.1 and was released in August of 2008. Just like previous revisions to TLS, this revision aims at improving the security of the protocol by improving the encryption and hashing standards. One of the primary goals of the TLS 1.2 revision was to remove the protocol’s dependency on the MD5 and SHA-1 digest algorithms.
For more details check the FAQ for this algorithm.