In Real Life

In Real Life, commonly known as "IRL," refers to anything and everything outside of the game, in actual life (real time)

Overview
Stuff from real life is referenced in-game all the time. There is not a single moment where you aren't talking about something from your actual life.

Weapons
Many weapons in the game, fictional or not, have had some sort of basis in real life. For example, the M416 series is based (or rather, copied) off of the real life HK416 series.

Weapons in real-life may also differ greatly from the weapons in-game; they may be more efficient, louder/quieter, or even more difficult to use or obtain.