"Special Ops game similar to Counter Strike"
Global Operations is a first-person action game that works completely independently. It is not the mod of any other game like Counter Strike.
This game has an interesting version with which you can play without being connected to the Internet. But the real action is in the net and you can be part of the ranks of combatants by choosing what type of character you want to be among the various professions available: explorer, command, doctor, sniper, demolisher, officer or artilleryman.
You can create your own games on a dedicated server, to learn to play just download the trial version that will give you access to multiplayer mode.