The Raspberry Pi Zero W is similar to the $5 Raspberry Pi Zero but adds in wireless LAN and Bluetooth support. But for getting this variant with WLAN and Bluetooth, the cost is $10 USD.
The Raspberry Pi Zero W uses the same Cypress CYW43438 chipset as used by the Pi 3 Model B to provide 802.11n WLAN and Bluetooth 4.0. The Pi Zero W remains with the same SoC running at 1GHz and being single-core, having 512MB RAM, and the same footprint.
More details on this wireless variant of the Raspberry Pi Zero via RaspberryPi.org.