namespace:
A labeled data structure that can contain its own definitions of variables, functions, files, etc.

An example of a namespace is a directory (aka, folder). Imagine two different folders – Folder0 and Folder1. Further, let’s imagine each contains a file named file-x, but the file-x in Folder0 is different from that in Folder1. Such a situation is possible because the full names of the two versions of file-x are different: one is Folder0/file-x, while the other is Folder1/file-x. We could also say that one version of file-x is from the Folder0 namespace, while the other exists in the Folder1 namespace.