What problem is solved by namespace feature in C++?

Question

Some problems can be solved by iteration and recursion . Decision to chose either of them is depend on what factors ?

Answer 1

Because it prevent name collisions that can occur especially when our code base includes multiple libraries. Using namespaces, All identifiers at namespace scope are visible to one another without qualification.
Formally:A namespace is designed to overcome this difficulty and is used as additional information to differentiate similar functions, classes, variables etc. with the same name available in different libraries. Using namespace, you can define the context in which names are defined. In essence, a namespace defines a scope.

Answer 2

Multiple providers of libraries might use common global identifiers causing a name collision when an application tries to link with two or more such libraries. The namespace feature surrounds a library's external declarations with a unique namespace that eliminates the potential for those collisions.
namespace [identifier] { namespace-body }
A namespace declaration identifies and assigns a name to a declarative region.
The identifier in a namespace declaration must be unique in the declarative region in which it is used. The identifier is the name of the namespace and is used to reference its members.