The MOAB (Mother of All Bombs) is a hidden killstreak available with any Strike Package. It's earned by getting a 25 killstreak, not including Strike Package kills. The MOAB works pretty much like the Tactical Nuke from Modern Warfare 2; it kills every enemy on the map and causes an EMP-effect for the enemy team by eliminating all enemy equipment, electronics and killstreaks for 1 minute.
The MOAB doesn't end the match. The team that uses the MOAB will have double XP for the remainder of that match.