Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer.
Environment variables are a set of dynamic-named values that can affect the way running processes will behave on a computer. They can be said in some sense to create the operating environment in which a process runs. For example, an environment variable with a standard name can store the location that a particular computer system uses to store temporary files—this may vary from one computer system to another. A process which invokes the environment variable by (standard) name can be sure that it is storing temporary information in a directory that exists and is expected to have sufficient space.
