Convocation is the ceremony at which students are individually recognized by their college or school for their academic achievement. This is the event where your name and achievements are called out on a loudspeaker as you walk across the stage, shake the hand of the dean or director, and receive a diploma cover (actual diplomas are mailed to you later via post). There are no fees to attend Convocation, other than what you pay for your cap and gown, and possibly, parking. Convocation is an optional event but if you are an undergraduate, this the only time your name will be called.
Commencement is a university celebration with all ASU graduates (not just those from your particular school or college). At this large ceremony, no individual names are called other than perhaps a student speaker. Groups of graduates are asked to stand up together. Expect a very large attendance. There are no fees to attend commencement, other than what you pay for your cap and gown, and maybe parking. This event is optional. More information about commencement.
Graduation is when you complete all your coursework/finish your program of study. To be sure your graduation from ASU is official, you must contact the University Graduation office, as well as speak to your academic advisor. To complete the graduation process, a fee is charged – it is paid online and all forms are submitted online as well, but not until all your coursework is complete. More about graduation.