Most cpus today actually have the memory controller on them, not on the board so the board speeds are almost a joke anymore. To be 100% honest the Pc12800 and stuff I don't know exactly what they stand for, but I know 12800=1600 MHz memory, 10600 = 1333 MHz, and 14900 = 1866 mhz.
CL9/10/11 is for cache latency, its basically how long it takes the memory to respond once the CPU tells it to do something. the lower the latency the better (assuming the same speed ram (in MHz) is involved). If you'll tell me what cpu and motherboard you have I can tell you how fast of ram you can likely run.