Yes, a wireless access point can support more than one computer.
The main difference is that a Access Point has no routing capability. It will have to be plugged into a router somewhere. It is only providing a wireless signal. A wireless router is an Access Point, but not all Access Points are necessary routers, if you follow what I mean.
I have a wireless router on one side of my house, with a network wire running from it to the other side of my house to a wireless Access Point. That way I have a continuous wireless signal throughout my house. It was not practical to place the wireless router in the center of my house, so this worked great for me.