The barbell row, also known as the bent-over row, is a weight training exercise that targets the muscles of the back, including the lats, traps, and rhomboids. It is typically performed using a barbell, which is a long bar with weight plates attached to either end. 

To perform the exercise, you will need to stand with your feet hip-width apart and bend forward at the hips, keeping your back straight and your knees slightly bent. From there, you will need to grip the barbell with an overhand grip, palms facing down, and lift it toward your chest, squeezing your shoulder blades together as you do so. Be sure to keep your elbows close to your body and avoid swinging the barbell or using momentum to lift the weight. 

It's also important to use a weight that is challenging but manageable and to avoid rounding your back or arching your lower back during the exercise.