IP Networking

Hello,
Please what's the difference between:
AND
Thank you so much

An IP address is how you talk to another computer over an IP network. Each network card has its own IP. You try connecting to 10.0.2.15, and IP protocol will find that computer and talk to it if it's there.

It must be unique on the network -- you shouldn't have two 10.0.2.15's plugged into the same local network, they'll conflict.

An IP address, combined with its netmask, netmask are sort of a combined house and street address. The netmask defines which part is local.

Code:

MASK   255 255 255   0
  IP   192 168  56 102
Local                0-254

Meaning, 192.168.56.102 can directly talk to any other network card with an IP address of 192.168.56.anything-else. If it were 192.168.57, it would have to forward the message along to a gateway and hope it knows where it belongs.

So the IP address is a unique ID for each computer, and the subnet mask defines which block of other IPs it can talk to.

Please, I have another question, I'm working on VirtualBox, I have two network cards, one for LAN and one for the NAT access mode that allows me to connect to Internet, how to know which card goes with which IP address?
and if
correspond to network card LAN or network card NAT?

Thank you so much