Explain the role of a transfer case in AWD/4WD systems.

A transfer case distributes power between front and rear axles in AWD/4WD vehicles. Part-time 4WD systems (like in Mahindra Thar) use a transfer case that can be shifted between 2WD, 4WD High, and 4WD Low. Full-time AWD systems have a center differential in the transfer case for continuous power split. Electronic transfer cases can vary torque distribution (0-100% front/rear) based on traction conditions using clutch packs or electronically controlled differentials.