A Galaxy Tab or other Android tablet can hold documents, chat or reference material beside your laptop. This is a software display connection: the tablet does not become an HDMI or USB-C video-input monitor. Any Display must run on both devices, with a working USB data connection between them.
Open both apps and connect the tablet to a USB port on the computer. Start without a hub or dock so you can rule those out if detection fails. Keep the tablet unlocked while checking Android prompts.
In Android Settings, find About phone or About tablet, then Software information if present. Tap Build number seven times to reveal Developer options and enable USB debugging. Menu names vary by manufacturer. The desktop app’s ‘Set up Android USB’ guide shows the required checks.
Open the Android USB notification and select File transfer. Accept the ‘Allow USB debugging?’ prompt for your own computer. If the prompt is missing, unlock the tablet and reconnect the cable. Revoke debugging authorization afterward if you used a shared computer.
Select the computer under USB connections in the tablet app. If a Wi-Fi entry also appears, check that you selected USB. If only charging works, try another data cable or port and recheck File transfer and authorization before changing display settings.
Choose Extend for independent workspace or Mirror for the same content. Arrange the tablet in Windows System > Display or macOS Displays and adjust scaling. Move a window across the configured edge, then test touch input to confirm the complete connection.
Check the data cable, File transfer mode and debugging authorization first. If another cable behaves the same way, check whether the computer recognizes the Android USB device and follow the desktop app’s USB guidance.
An extended display may simply have no windows yet. Check its position in the operating system and move a window there. On Mac, also check Any Display’s Screen Recording permission. A single protected video appearing black is a different problem from USB discovery.