A chin-up is a strength training exercise that primarily targets the muscles in the upper body, particularly the latissimus dorsi, biceps, and trapezius. To perform a chin-up, an individual hangs from a horizontal bar with an underhand grip, pulling their body upward until their chin surpasses the bar. This exercise can be done using various grips and can be modified for different fitness levels. Chin-ups are often included in workout routines to build upper body strength and improve overall fitness. They can be performed in gyms or at home with a suitable bar. Regular practice can enhance muscle endurance and contribute to better posture.