For the most part, barbells are slightly better than dumbbells in terms of building muscle, gaining strength and creating an efficient workout.
The biggest difference between the two is the amount of weight that you can use A barbell already weighs 45 lbs and can be loaded with enormous amounts of weight.
Barbells provide several advantages over dumbbells. These include ease of use, improved ability to progressively overload certain exercises, and the advantage of being able to lift more weights.
As a general rule of thumb, you will be able to lift anywhere from 15-25% more weight with a barbell than a dumbbell. This is primarily because it is much harder to lift heavy dumbbells than heavy barbells.