A job objective is also known as a career objective. The job objective is usually listed in CVs and resumes to indicate the applicant's career track and aspirations. The objective is used as a motivational element in the job application to indicate the applicant's area of interest in relation to the position.

Job:Senior sales officer

Objective: To develop my sales skills through experience in demanding and rewarding sales roles.

As you can see, the objective fits well with the type of job. A sales person would naturally be looking for a higher profile role as part of a career progression.