From Press Release:
Welcome to Season Four of Call of Duty: Modern Warfare! Launched today, Modern Warfare Season Four includes a new operator, Captain Price, three new free maps across Multiplayer, Ground War and Gunfight. Additional free content includes three new Multiplayer modes throughout the season.
In Warzone, fans can experience new ways to play with in-match updates, including Fire Sale, Jailbreak and Supply Chopper. Warzone players can also enjoy two new limited time modes during the season, including Juggernaut Royale and Realism. Additionally, Warzone Rumble expands players’ squads in an intensive 50v50 large team battle.
For more information about Season Four, head to the Activision Blog post, here: https://blog.activision.com/