Adjustable dumbbells are versatile weights that allow users to change the amount of resistance by adding or removing plates or adjusting dials. They combine multiple weight levels into a single set, making them space-efficient and cost-effective for home workouts. Adjustable dumbbells are ideal for a wide range of exercises, offering the flexibility to easily increase or decrease weight for different strength levels and routines.

Fixed dumbbells are weights with a set, non-adjustable weight, typically consisting of a solid handle with permanently attached weight plates. They come in various sizes and are commonly used in gyms and home setups for exercises like curls, presses, and rows. Fixed dumbbells are durable and convenient for quick transitions between exercises since there's no need to adjust weight settings.

Dumbbell sets consist of multiple pairs of dumbbells in varying weights, offering a range of resistance levels for different exercises. These sets can include either fixed or adjustable dumbbells and are commonly used in strength training to target various muscle groups. Dumbbell sets provide versatility for exercises like presses, curls, and squats, making them ideal for both home gyms and fitness centers.