What Does Tethering Mean?
Tethering is the sharing of wireless connectivity through linking wireless-connected devices to unconnected devices. This modern telecom service component is focused on devices like smartphones and tablets.
Techopedia Explains Tethering
In terms of seeking out more versatile wireless connectivity, tethering is an alternative to another kind of telecom service known as a mobile hotspot. Telecom companies now offer mobile hotspots that provide local wireless connectivity to unconnected devices without the hassle of tethering one device to another. These are typically sold through a subscription model, with an upfront price for the hardware itself.
As a concrete example of tethering, some iPhone users can use Apple’s engineering and features to share the iPhone’s connectivity with personal computers (PC), MP3 players and other devices. This can be done through Wi-Fi connections, Bluetooth or Universal Serial Bus (USB) cabling. The iPhone 4 and newer versions support tethering, which Apple has denoted with labels like "personal hotspot."