USB4, often informally called USB 4.0, is a USB interface specification for connecting computers and peripherals. It supports high-speed data transfer and can carry display signals; capabilities such as maximum speed and power depend on the specific USB version, devices, and cable. USB4 builds on technology from Thunderbolt 3, but USB4 and Thunderbolt are not interchangeable labels.
In cyber security, a USB connection is a potential point of interaction between a computer and external hardware. A malicious or compromised peripheral may attempt to exploit software, misuse device functions, or deliver harmful data. USB4 itself does not imply a security flaw: risk depends on the devices, firmware, operating system, and controls in use. Organizations can reduce exposure by restricting unknown peripherals, keeping drivers and firmware updated, and using device-management policies. In the article context, USB4 is simply a modern interface contrasted with Windows 98; no attack or vulnerability is described.