Muslims are urged to do this by the Prophet Muhammad and doing so is said to bring blessings for the entire week. Reciting Surah Kahf on Fridays is a Sunnah.Prophet Muhammad received it prior to the Hijrah/Migration to Medina. It might be concluded from this that it was revealed while Prophet Muhammad was in Mecca. You can read Surah Kahf PDF Free, a Meccan surah, both online and offline, and with Surah Kahf PDF English.
For a better understanding, read the surah’s translation in Urdu by using the Surah Kahf PDF read online option.