Basically, a wireless router is an access point (AP) with router capability. Sometimes for some reasons you may not need another router to broadcast a network wirelessly. You need an AP and not a wireless router for broadcasting a local area network wirelessly.

Why?

A wireless router has different network ID between it's WAN and LAN connector. That's what routers are for, connecting (routing) two or more different network IDs (in this case: LAN network and WAN network).