The scope is the realm or dimension in which your variables and objects exist. All the things in this dimension must have their own unique name. Function and methods can define any number of variables
This is the highest scope level PHP has. It contains the $_GLOBAL var for the PHP instance.
Function or Method-level
Namespacing is a technique used to avoid collisions with other objects or variables in the global namespace. They’re also extremely useful for helping organize blocks of functionality in your application into easily manageable groups that can be uniquely identified.