Original: Despite the title Ace Attorney, the game does not feature a defense attorney as the protagonist, but rather a recurring character of the series, Prosecutor Miles Edgeworth.
Simplified: Ace Attorney Investigations: Miles Edgeworth plays differently from the other games. The games in the Ace Attorney series are courtroom dramas, but Ace Attorney Investigations: Miles Edgeworth focuses on pointing and clicking around the area, moving Edgeworth around the crime scenes to find evidence.