This particular format focuses in on the professional skills you have developed over the years. It does not place emphasis on dates but focuses in on skills.
Functional resumes are similar to the chronological but the approach is different.
An employment objective must be clearly in mind since this type of resume focuses in so strongly on skills. Functional resumes are used by experienced individuals changing career fields and for those pursuing employment in nonprofit organizations. Entry-level types whose track records do not justify a chronological resume. Career changers who want to focus on skills rather than credentials. Individuals whose careers have been stagnant who want to focus to the skills that can get a career under way, rather that on the history in which it came about.