Does Halo have "levels"?

Halo was originally described as seamless, and it was promised there would be no level loading screens as most first person shooters now have.

It was assumed that perhaps this meant a stutter-loading scheme such as used in Half-Life, where rather than long waits between large levels, areas of the game would be loaded in short pauses as the player progressed through the game.

While it is known that the player will not be able to traverse the entire surface of the Halo during the game, it still apparently features no loading screens, although there are instances of what the developers have called insertion cinematics that introduce various encounters during the game.