Typically, the candidate and employer have opposite goals during the salary negotiation. Your goal should be to bring home the best salary you can for the work you will be doing. Your employer's goal will be to offer you the most equitable offer he/she can, while also saving money for the company.
Keep in mind that your employer wants you to be happy and satisfied in your job. A salary that is lower than you deserve may ultimately cause you dissatisfaction and a desire to leave. This is where your goals and the employer's goals meet in the middle. Although this might sound like an adversarial situation, both parties are working together to create a win-win situation.
