Yes it does make a difference to how far the wireless goes but not so you would notice
802.11 is the IEE standards for wireless technologies
The a,b,g are relating to the frequency the radio is operating on and the speed of throughput.
802.11a is 5Ghz card with a throughput of 54Mbps in the UK it can also have a turbo mode added but is not legal in UK this would allow 108Mbps
802.11b is 2.4Ghz card with throughput of 11Mbps
802.11g is 2.4Ghz with 54Mbps
It is possible to have a card which does 11b and 11g
Hope this answer your question and no i am not a nerd i have just sat through a 4 day training course on wireless technologies which was very boring but at least i have learnt something!