You get 3 separate scores on the GMAT.
Math/Verbal: Scale: 200-800. B-Schools care the most about this score.
Integrated Reasoning: Scale 1-8. Since this section is new, B-schools will not weigh this section heavily. This may change.
Essay: Scale 1-6. B-Schools care the least about this.
When you submit your scores to schools, you submit all the scores. But you don't find out all the information at the same time. Your math/verbal score is calculated instantly, so you'll know it within one minute of your finishing the test. Then, in about 3 weeks, you'll be sent your other scores, the IR and the Essay.