Thunderbolt 3 is a high-speed external connection standard that uses a USB-C style port to carry data, display signals, and power. It is commonly used for fast storage devices, docks, and expansion enclosures because it provides very low latency and high bandwidth compared with older external interfaces.
In cyber security, Thunderbolt 3 matters because fast physical access can also mean fast risk. A connected device may expose large amounts of data, and a compromised or untrusted peripheral can become a path for theft, tampering, or persistence if endpoint controls are weak. Defenders pay attention to device authorization, port restrictions, encryption on attached storage, and safe handling of removable media. In practice, Thunderbolt 3 is often seen in workflows that need speed, but secure use depends on trusting the hardware chain as much as the interface itself.