Nothing is more important than having an up to date and carefully prepared resume. The right resume for the job is often the difference between getting an interview or not. For most employers, chronological resumes are the universal preference. They want to know what the progression of your experience has been.
Chronological resumes are also easier to verify.
Functional resumes are usually used by job seekers to highlight skills versus past jobs or to avoid emphasizing large gaps in employment history. A listing of educational courses and experiences relevant to employment. Try several formats, getting feedback from career counselors, professionals in your field. Keep the sentences short and tight. They give potential employers a first impression of you.