Hotspot is the name of a wireless internet point of access.
You can create an hotspot using your PC if the PC is connected to the Internet trought LAN cable (so the PC doens’t use the wifi antenna itself to receive Internet data).
At this point, since the antenna is inactive, it worths using the antenna to send the data to other devices.
In this way we would have created a hotspot.
How to do ubuntu 16.04 in Italian?
Check it in italian.