An elliptical trainer is a stationary exercise machine that simulates walking, running, or climbing without putting stress on the joints. It features two foot pedals that move in an elliptical motion, allowing users to engage both their upper and lower body. Many models come with adjustable resistance levels and built-in workout programs to enhance fitness routines. These machines are popular in gyms and homes due to their low-impact nature, making them suitable for people of all fitness levels. Users can also monitor their heart rate, calories burned, and workout duration on the machine's display, helping them track their progress effectively.