The two are different and separate from each other. Increment is normally drawn as a matter of course, unless it is withheld by a specific order. This is more so in the government sector and a uniform rate of 3% increase of basic pay is allowed. Evaluation is process to decide the contribution made by an employee. In a few organisations increment is awarded based on the evaluation, this is followed more so in the places without any formal rules where there is no limit on the quantum and it would vary from individual to individual.