If you are trying to build a home gym on a limited budget, you may have to make a choice whether to purchase a dumbbell set vs. barbells for the start of your gym. I will go over the advantages of a dumbbell set in this article. You can refer to my article The Advantages of Using Barbells over Dumbbells for Your Workout Routine for the reasons why you would want to use barbells over dumbbells.
Dumbbells allow you to do a wider range of activities. For instance, Flys and Lateral Raises cannot be done with a barbell set. In addition, exercises like Wrist Curls are better done with dumbbells as they allow for a greater range of motion.
Dumbbells work a lot of your stabilizing muscles. For instance, a Barbell Shoulder Press will work the deltoids but the bar provides a stabilizer that your body does not have to work for. A Dumbbell Shoulder Press forces each arm to act independently so you have to carefully concentrate and stabilize your muscles in order to perform the movement correctly. The trade-off to this is that you likely won't be able to use as heavy of a weight as you would with a barbell. You also must concentrate on having good form as dumbbells make it easier to cheat if you are performing the movement sloppily.
Dumbbells will show weakness in one arm over the other. If you find yourself unable to perform the same amount of reps with the same good form for one arm over the other, you can rectify the situation by working out that arm more and having it catch up with the other one. Doing barbell exercises will cause the stronger side to cover for the weaker side most of the time. The downside to using dumbbells is that you may be cheating with weak arm and not even realize it. It's a lot harder to self-analyze sloppy form while using dumbbells.
When you work out with dumbbells, you can concentrate on one arm at a time. This is particularly effective for arm exercises like Wrist Curls, Concentration Curls and Kickbacks. You can really focus on the pump of the muscles in one part of your body as opposed to splitting your concentration between the muscles in your left and right arms.
I recommend dumbbells to those people who intend on using lighter weights for fitness and toning with some gain in strength rather than trying to bulk up and get more powerful. If you are using heavy dumbbells for certain exercises that put you in a compromising position I recommend that you have a spotter or two in order to help you safely pick up and drop the weights.
More of my workout advice:
Are Bowflex SelectTech Adjustable Dumbbells suitable for you?
Should you buy Bowflex SelectTech Dumbbells in a store or online?
Why you would want to use barbells for your workouts
How I lost over 40 pounds in 6 months with some simple diet changes
Upper body exercises with no equipment needed
Lower body exercises with no equipment needed
Cardio exercises with no equipment needed
The Different Ways of Doing Dumbbell Bicep Curls
Inflatable Exercise Ball Exercises for Men