If you downloaded a RAR file and this string was provided alongside it, it is almost certainly the archive password.
If this was listed as a "checksum" or "hash," it is used to verify that your download isn't corrupted. 7895420D4FG54HU1B rar
In some modding communities (like The Sims or Skyrim ), specific alphanumeric codes are used as unique IDs for custom content files. If you downloaded a RAR file and this