In a peer-to-peer wireless networks client computers communicate with each other  without the use of physical cable.  It use a wireless (radio) protocol that enable each device on the network to communicate the same way as a wired network.  Wireless networks are less costly than wired networks.  No cables have to be run to each device.

A wireless Peer-To-Peer network is usually setup with a Wireless Access Point (WAP) acting as a central switch between devices.  However, it can be setup without the use of a Wireless Access Point whereby each computer can be configured to communicate directly with each other.

You can place a wireless printer on the network if it has bluetooth or build-in wifi capability.