What is a namespace in programming language?

• A namespace is a framework for their identifiers (class, methods). 
• Namespace provide a way of grouping the names that are assigned to elements (class, methods) in a software application so that they don’t conflict with other class, methods names. 
• Namespaces are heavily used in C# & other OOP language & all .NET Framework classes are organized in namespaces, to be used more clearly and to avoid confusion.

C 7.0 in a Nutshell: The Definitive Reference