This document discusses wireless networks and their applications. It describes wireless personal area networks (WPANs) which connect devices within about 10 meters, including Bluetooth. Wireless local area networks (WLANs) connect devices within a larger area and buildings, about 100 meters, using Wi-Fi standards like 802.11. WLANs use access points to connect to a wired network and can be configured in ad-hoc or infrastructure modes. Mobility and flexibility are key advantages of wireless networks. Security measures that can be applied include firewalls, user authentication, data encryption using WEP or WPA, and limiting access through the network adapter settings.