Inferno is one of the CS: GO maps that have been part of the game since the early days. It was in the first Counter-Strike game and also in its sequel Condition Zero. When the original game was remade with Source engine into Counter-Strike: Source the map was kept but it was heavily modified. The version we now have in CS: GO is based on the Source variant.
Inferno is a bomb scenario map. In this scenario, each team must complete certain tasks to achieve victory. The terrorists’ team has to plant the explosive and prevent the enemy team from defusing it for a certain period of time. The alternative victory condition is to kill all members of the opposite team. The counter-terrorists fight to restrain the other team from planting the bomb. If the bomb was planted, they can still achieve victory by disarming the bomb. The counter-terrorists can also win by taking down all their enemies but only if they do this before the terrorists deploy the bomb.
The map is currently among the active duty maps. The last map update was in October 2016. Bombsite A went through changes that made it a more suitable location for fighting. The entire area was made brighter by removing the roof. This decision led to an increased use of smoke grenades and made sniping easier. The dark bedroom was changed into a cubby. The way to the balcony is more open after the update. Bombsite B was changed as well. The road to it was made wider so those who assault it have more room to move. The abandoned yellow car that was sitting at the end of the path was replaced by some barrels that can be destroyed. More changes that add visibility were made. The middle side of the map was also updated. Players can walk on the part between the middle and the alt-mid. The light pole was removed. The T Spawn has a second exit.