Barking is simply one way dogs communicate and can mean anything from playfulness to danger. Some dogs bark because they are:
Chained to a fixed point and don’t have enough room to move around
Being provoked deliberately or unintentionally by people or other roaming animals
Not getting enough exercise
Not properly trained
Lonely, sick, hungry, or generally neglected
Chronic or excessive barking is a sign that something is wrong and can be a nuisance to others in the community. Sometimes stopping a dog from barking can be as simple as taking care of their basic needs.