1) A belt drive uses a looped strip of flexible material to mechanically link rotating shafts. Belts are looped over pulleys to transmit power between shafts or track their relative movement. 2) Belt drives are simple, economical, tolerate some misalignment between shafts, dampen noise and vibration, and are highly efficient. However, they have limits on speed, power transmission, and operating temperatures. 3) Designing a v-belt drive involves determining factors like the application factor based on power and speed, selecting the proper belt type and pulley diameters and pitch length, calculating the center distance and contact angle, and determining the number of belts needed based on the rated power of each