Ok here is what it does...
The easiest way to explain it is to use the telephone and a walke talke... Whey you are on the phone and you and the person you are talking to say something you both hear it... So you are able to send and receive at the same time... This would be full Duplex
On the other hand you have walke talkes... Only one person can talk at a time.. this would be half duplex....
the 10/100 thing is the speed at which the network runs at... 10mbs or 100 mbs... Most of the equipment that you can buy now is 10/100 compatible... Meaning that if you plug in a 10mbs device that area of the network will be slowed down to 10mbs... even if the network is able to run at 100mbs... Most of the time you will see Hubs, stupid devices, running at 10mbs... We now have 10/100/1000 standards.. what you want to avoid doing is mixing 10mbs with 1000mbs or the other way around.. this creates a bottleneck and that leads to slow network proformance... The thing that I have setup at my home in Illinois, I am at Purdue University right now..., is to seperate my wireless and ethernet based networks to eliminate the slow down that occures with the wireless... Wireless only get about 25-35mbs of true speed on a 54g system... With this bottle neck avoided I dont have to worry about my ethernet connection taking a hit because I am also using that router for my ethernet stuff...
So I guess I got on a tangant... but here is a quick summary... lol Full vs Half duplex depends on whether it can send AND receive data at the same time.... 10/100/1000 is the speed at which the network operates at... The higher the better... but also the more expensive... Hope that helps!! Seems like some people are setting up some networks around here... A router/switch/hub qestion and now this.. Very cool! have fun!