Technically they would be called 'Nodes'
A mobile phone.
answer: node
Any device on a network is called a 'node'.
It's call a NIC (Network Interface Card)
a drive
If you have a computer which is not connected to Internet (or other networks, LAN, Wireless network...) you can call it a standalone computer.
They use a radio inside the device to communicate with a tower. That tower connects to the carrier's network, and from there is forwarded to another carrier's network. Basically the receiving end is the reverse of the sending.
This is known as Voice Over IP, or VoIP. With this, your phone is connected to your Internet-connected computer. When you make a call, your computer translates it to IP(Internet Protocol). It then sends that call out via the Internet. If the recipient has VoIP as well, the process works in reverse for them to receive the call. If the recipient doesn't have VoIP, your call goes to a translation device near the recipient. The device then takes the data, translates it back to a normal voice call, and sends it to the recipient through standard phone lines.
Probably the UK - since that's our 'standard' name. The americans call it a cell-phone (due to the way the mobile network transfers a call between adjacent towers to keep the call connected.)
There are several ways to play call of duty, if you have a device that does not connect to the internet then there are single player options. Also there is a campaign option which is single player and you do not need to be connected to internet.
Raw data
A "LAN" ... which stands for "Local Area Network". If the network is formed by a Bluetooth wireless network, it's commonly called a "PAN", or "Personal Area Network". This refers to the short distance generally between your Bluetooth devices, which may include computers, headsets, mobile phones etc.