descriptions of nokia software

hai, sir....
i am a beginner in mobilephone....n i want to learn basically about mobile software.....cos i am confuse with term in nokia .....
like asic 2 n else....
like why BB5 mobile can't easily unlock and why dct4 is easiliy unlock...
there is so much info i read...but it's make more confused...may be because i have no right reference as basically...
thanks in advance...