2 or more
challenge lobby
Your face thats the answer
The first game released November 2007 as Call of Duty 4 Modern Warfare and new Modern Warfare series games titles have been released every 2 years since
You must complete different challenges (Note:You dont have to be online to aquire levels or titles)
By completing challenges or raising in rank, same for emblems
Modern Warfare 3 is not available on the Vita and there are no plans to bring it to the Vita. Activision has said that there may be future Call of Duty titles available on the Vita.
http://callofduty.wikia.com/wiki/Callsigns
You gain titles and emblems by completing certain challenges on multiplayer, check your barracks for the challanges. Here is a list of all the titles and emblems for call of duty modern warfare 2 on the Mordern warfare wiki: http://callofduty.wikia.com/wiki/Callsigns
well call of duty and modern warfare are the same it is called Call of Duty: Modern warfare and then came call of duty: modern warfare 2
You can get them many ways such as leveling up, completing challenges, etc.
2 Call of Duty titles have been released for the original Xbox. They are Call of Duty: Finest Hour and Call of Duty 2: Big Red One.8 Call of Duty titles have been released for the Xbox 360. They are Call of Duty Classic, Call of Duty 2, Call of Duty 3, Call of Duty 4: Modern Warfare, Call of Duty: World at War, Call of Duty: Modern Warfare 2, Call of Duty: Black Ops and Call of Duty: Modern Warfare 3.(This information is as of 18 September 2012)
Call of Duty 4: Modern Warfare came out first. This is the first game in the Modern Warfare series, and Modern Warfare 3 is the third game in the Modern Warfare series.