Yes, that's how a monster's level (for the purposes of player characters) is listed.
Racial Hit Dice
Think of racial hit die as character levels. They both grant base attack bonus, HP, saves, and feats. Racial HD don't grant class features, though - instead, the monster has special attacks and special qualities based on its race.
A lot of monsters are really strong, but have relatively few class levels. For example, a rakshasa has 7 racial hit dice, but it much more powerful than a 7th level character - in addition to sorcerer casting it also has spell resistance, damage reduction, shape-changing, etc. Level adjustment is an estimate of how much these "extra" abilities are worth, in terms of levels. So a rakshasa player character would be considered 14th level. It is not possible to play a 13th level rakshasa without introducing some changes to the game.
After you add up Racial Hit Dice and Level Adjustment, the character proceeds as normal. A rakshasa with 1 level of sorcerer is level 15 - 7 RHD, 7 LA, 1 class level.