The console is a command prompt that lets you use developer-like functions. I’ll just copy everything from the FO3 guide here. Since the engine is identical to FO3, the console commands are the same.
To see some gameplay with these mods in action, look here. These mods will make your game look better, play better and just add loads of new content. Keep in mind that many of the mods listed here require most if not all of the DLC, so be sure to get them!
With those statistics, we decided it would be smart to give everyone a list of essential mods to download. According to Steam, Fallout New Vegas still has thousands of active players every day.