A portable USB to HDMI adapter connects a computer or laptop with a USB port to a monitor, projector, HDTV, or other device with an HDMI port. It can expand your laptop's screen into a monitor and supports up to 1920x1080 resolution. The adapter has two modes: Mirror mode and Extended mode. It is compatible with Windows and macOS laptops and can be used for watching videos, video teaching, conference projection, and other scenarios.