Being allowed (or required) to use one’s personally owned device, rather than being required to use an officially provided device.

There are two major contexts in which this term is used. One is in the mobile phone industry, where it refers to carriers allowing customers to activate their existing phone (or other cellular device) on the network, rather than being forced to buy a new device from the carrier.

The other context is in the workplace, where it refers to a policy of permitting (or requiring) employees to bring personally owned devices (laptops, tablets, smartphones, etc.) to work, and to use those devices to access privileged company information and applications. AKA, Bring Your Own Technology (BYOT).