How can we connect several computers in one network? What is the best option LAN or WAN? Give reasons.

using the LAN. All the  computers will connected to switches for manages the traffics then these switches will connected to Router to allows the computers to get access to the WAN.

Via wired or wireless networks

the best option is LAN

The reason it's more secure

By using the LAN. The reason is: the computers will connected to switches for manages the traffics according to MAC addresses then these switches will connected to Router to allows the computers for connected to the remote networks but I think all these are depending to the company requirements

If you have devices in the same area . so i will prefer you lan . wan is used to communicate different networks

to connect several computers we can but it in LAN through switch and the best option for several computer is LAN if it in the same area but if it in deffirient area it should be WAN