Voice projection is an important part of some professions. In singing and public speaking, speaking loudly and clearly is essential.
A major part of projecting your voice is using a proper breathing technique. Learning to breath deeply and filling your diaphragm rather then just your lungs can be taught and practiced. Good level breathing directly contributes to the quality of your voice.
Proper breathing and projection from your diaphragm is an important part of playing many instruments as well. Playing an instrument takes more practice than singing, but many of the same principles apply.
It often takes years of performing and practice to reach the breathing and projection found in a Broadway musical. These are people who have been training for most of their lives to make the big stage. Not to mention the competition at that level is stiff.