Not sure if you've already received an answer for this question or whether you've figured it out for yourself yet.. But i'll contribute anyway
Performance management refers to aligning the individual employees objectives with those of the organisation to ensure maximum productivity and motivation from the employee as well as these objectives being reached. Eg if an
employee is seeking to further improve their skills and experience in the workplace, and the
employer is seeking to maximise profits, through performance management a HR manager could develop a new training program in communication for the
employee so they could better deal with customers, which would lead to increased sales and therefore increased profits.
The success and effectiveness of this training program could then be measured with a performance appraisal; when an employee receives feedback about their performance with regards to their role within the organisation. ie it's no good telling an employee their sales figures have increased and are therefore being productive within the organisation if they have other job responsibilites that aren't being fulfilled.
Hope this helps

and that it's not too late!