Those numbers represent liability limits.

The first number is the maximum coverage for bodily injury for one person injured in an accident (thousand).The second number is the maximum coverage for bodily injury for one accident (thousand).The third number is the maximum coverage for property damage for one accident (thousand).

Therefore, if you have 10/20/10 the minimum liability limits are $10,000 for bodily injury liability for one person in an accident, $20,000 for all injuries in an accident, and $10,000 for property damage in an accident.