Red Cross CPR levels?

Ok so i am currently a lifeguard, and am attending fire school. My current certifications are: Lifeguarding/first aid and CPR-AED for lifeguards. In the past, my cpr aed cert card said for the professional rescuer, so im curious as to whether or not "lifeguard" carries the same weight as "professional rescuer" therefore making it so i dont have to recertify while becoming a firefighter. Also, my current cpr and last one say valid for 2 years, i've heard many ppl say they are only valid for one. why this discrepency?