How does a USB wireless access point work?

I’ve been thinking about getting a usb wireless access point, but I’m not sure how the device (and everything connected through it) actually works with the rest of the network. I’m looking to connect my laptop and iPod to the internet wirelessly through my computer that is plugged in with an ethernet cord.

Long story short, I want to know if the main network will see the individual devices connected to the wireless access point, or will it only see the computer that has the physical connection.

Edited for a bit more clarity.