With Xbox Live and Playstation Network, online games are both fun and challenging. You can play with friends of choice or have the online network choose an opponent for you. There is a simple ranking system which you can learn more about here. However, there are more ways to get involved online than just play 1v1 matches with other players. The other four online game modes available in FIFA 08 are explained below.
The Interactive Leagues game mode allows you to represent your favorite club team and play against other clubs in the league of your chosen team. By playing these matches according to real-life season fixtures, you can establish a rank within your club and your club collectively creates a rank against others in the league. Unfortunately, now that the 2007-2008 season has gone, this Game Mode is no longer active. If you are interested in this game mode, I would recommend buying the newest version of FIFA, which all feature this game mode.
From FIFA 08's online play menu (Xbox Live for Xbox) you can create and customize your own leagues to play with your friends. You can specify rules for who is allowed to join and game rules and customize your league logo and trophy.
Be a Pro: Online Team Play
Be a Pro online game mode is exactly the same as the offline version, except every player on the pitch is controlled by another online player. Keep in mind that the FIFA 08 online version of this is pretty dead, at least at the time of writing. So, if you're really interested in the Be a Pro game mode and you would like to take your skills online, I'd recommend buying a newer version of FIFA, which all have the Be a Pro game mode available for both online and offline play.
As explained above, these are just traditional 1v1 matches of football. This does not differ much from the offline experience. There are two types of online games, Ranked and Unranked. Ranked affects your online rank and Unranked does not. Note that custom matches can be either of the two types and you can also use the FIFA 08 Lobbies to find an opponent, although they are also pretty dead at the time of writing.