The type of exercise primarily focused on building strength is called resistance training, which involves using weights, resistance bands, or bodyweight to create resistance against muscle contractions. This form of exercise promotes hypertrophy, enhancing muscle size and strength while improving overall functional fitness. Resistance training is effective for increasing muscle endurance and boosting metabolism as it promotes calorie burning even at rest. Incorporating a variety of exercises targeting different muscle groups ensures a well-rounded approach to strength training, contributing to improved body composition and physical performance.