1 year multiple entry VISA

I wish to move to the Philippines, I have contacted the Bangkok Philippines embassy and they tell me I can purchase a 1 year VISA.

I believe it may be this one: 9(a) Multiple Entry (1 year validity) A/B.

I am not sure what the A/B Means, and if it is indeed this VISA I need, I do not want to renew a VISA all the time.

I hope this means I do not need to leave within the year, and if this is the correct VISA, why do people enter on the free stamp and renew their VISA all the time, am I missing something?

Please offer me any information you can.

not a one year visa  -only means you can enter as many times as u want during that year  ,as per previous post  u just get 59 day visa and renew every 2 months