Full form of GB,KB and MB:
Full form of 2G,3G,4G:
The G in 2G, 3G and 4G stands for Generation, and they refer 2nd, 3rd and 4th generation of wireless technology. The newer generation is faster, more secure and more reliable.
Full form of SIM :
A subscriber identity module or subscriber identification module (SIM), widely known as a SIM card, is an integrated circuit that is intended to securely store the international mobile .