In our code, we can avoid repeating the namespace of a library (when we are using it too often) when using an associated function by simply using a shortcut of writing 'use namespace ’ at the top.
However in larger codes, you may be using functions from several namespaces and may have written 'use namespace ’ at the top for each namespace used. The problem is, different namespaces may have functions with the same name and the system wouldn’t know which namespace we are referring to for that function when calling it our code. The system may use the wrong namespace or give an error.
