Directional communication is data transfer that depends on the sender and receiver being physically oriented or aligned so a signal can reach its intended destination. Infrared links such as IrDA are a common example: unlike broadly broadcast radio, their signals generally travel along a narrower path.
Directionality can limit unintended reception, but it is not a security guarantee. Attackers may still intercept or manipulate a link if they can position suitable equipment, and devices may rely too heavily on physical alignment as a substitute for authentication or encryption. In practice, defenders should inventory directional interfaces, understand what commands or data they carry, and protect them with appropriate access controls and cryptographic safeguards.