A wireless USB dongle is a small adapter that converts WiFi signals to a USB signal.
Adapters or dongles are often used interchangeably to describe a small wireless electronic device.
For example, a wireless mouse that has its own USB adapter that transmits wirelessly to the mouse is often called a dongle.
Most often, when the word wireless dongle is used it is meant to reference a WiFi device.
These small dongles can connect to any computer that has a USB port and receive a WiFi signal. This allows it to connect to a network and get online.
This is useful for various reasons, from a computer that has no wireless built-in to a laptop that has a broken wireless card or simply needs upgrading.
Wireless dongles use the same WiFi protocols as smartphones, tablets, or routers, making them helpful in getting a computer on a wireless network.
The protocols used are backward compatible as new ones are introduced.
WiFi protocols all start with the number 802.11, followed by a number a/b/g/n/ac/ax to indicate the version.
For example, the newest protocol, 802.11ax, also called WiFi-6, is also the fastest and works in the 5GHz wireless frequency.
Older protocols are still widely used and working the 2.4GHz range, including Wireless-N (802.11n)
Some dongles are small and don’t have a good range since the built-in antenna is smaller.
These are still widely used since they are very small and out of the way. These type of small adapters have about the same range as a laptops built-in wireless card.
The words dongle and adapter can be used interchangeably. So if the word dongle is confusing, simply replace it with an adapter.
Even though a wireless dongle usually means a WiFi USB adapter, it can also be sometimes used in another context such as a computer mouse transmitter.