title: MD5 file integrity check
body: <p>I know that hash functions make calculations, and the final result is string with fixed length. They are used to verify that files are the same - downloaded files, for example. There is hash presented by the owner of the file, and so the integrity check in this case is comparison of the 2 hashes.</p>
  
  <p>So is this the only file integrity check or there is another thing?</p>