I have a few questions about networks.

1. What exactly is a VLAN? I have googled several times, but i am not getting any good explanation and am getting different explanations from different sites.

2. My DHCP gives out 192.168.1.x IP's which seems that most routers give out. Is this specific to home networks? Could i change it?

3. Different Subnets? What exactly is a subnet? Why would i want to have different subnets on my network? And would my devices still work together?

I tried looking for a general Networking tutorial that would explain everything, but I couldnt find one. I figured if i wanted to learn as much as i can about networking i could take a course at my uni, which i may end up doing.

Any info would be help full