What is an access point?
An access point (AP) is, formally, a device containing a radio that is used to create an access network, bridge network or mesh network. The AP contains the Distribution System Service.
In a home environment, an AP is a bridge between a wireless client device (phone, tablet, computer, etc.) and the internet.
In a business environment, an AP is a bridge between a wireless client device and the internet and to other network resources such as printers and servers.
The term "access point" is often colloquially analogous to "router" which acts in the same way access point does, but in a home environment.