Environment variables are variables that describe the environment in which apps and programs run. In Windows, environment variables have a name and value. For example, the variable windir (short for “Windows directory”) may have the value “C:\Windows” or another path where you installed Windows.

Setting up PATH. Many programs need to know where to find specific files, and the PATH variable tells them where they can find what they need. Those programs automatically look for a PATH variable, so you don’t have to type it all in every time you run the program. This variable has a value consisting of many user directories. These directories are set by the different applications installed on the computer, and they vary widely from system to system.

The concept of environment variables exists in most operating systems, from Linux to macOS to Windows. In principle, they mean the same thing but the way they are implemented and used differs.

• In Windows 10, use the search box on the taskbar to look for the environment variable. Then, click or tap on the “Edit the system environment variables” search result.

• Single click on EnvironmentVariables..

• A new window will pop up and there you can see user variables, Single click on New, and another window will pop up.
  
• Add Variable name & Variable value. e.g If we want to add Blender version 2.83 ¹⁾

   e.g: "C:\Program Files\Blender Foundation\Blender 2.83\blender.exe" 

  
  

• After adding Variable name & Variable value click on ok and the path added will look like this.