What is the difference?

[Hunter-Hucast]

What is the difference between Normal mode, Battle mode, and Challenge mode! After I know you can lock this topic!

[Sitka]

Normal mode, in most platforms, has four levels including normal, hard, very hard and ultimate - these levels are playable online (BB), offline (DC, Xbox, GC) and both (DC, Xbox, GC). This is normal play and can be done with one or more players, up to four.

Challenge mode is done with a specific set of rules and starting levels/weps/setups and can be done for both Episode 1 and Episode 2. Cmode requires 2-4 players (cannot be done solo unless using two controllers offline)to get through several stages (9 on ep 1 and 5 on ep 2) under a set time (7 hours on ep 1 and 5 hours on ep 2) to get a ranking. If the time goal is achieved, an s-rank weapon is awarded and the s-rank weapons online are pretty decent. The offline weapons are mostly joke weapons.

Battle mode has several sets of rules and involves two or more players fighting each under the rules that both parties have agreed to.

That's the basics, read the guides to learn more.