What are environment variables?

Environment variables are dynamic values that provide information about the environment in which processes run in an operating system. They play a crucial role in configuring how applications and processes behave. These variables can store various types of information, including system paths, user preferences, and settings that applications can access when they are executed.

For example, the PATH environment variable tells the operating system where to look for executable files, while the HOME variable identifies the current user's home directory. By changing these environment variables, users and administrators can influence the behavior of the system and applications without needing to modify the applications themselves. This dynamic capability allows for greater flexibility and customization in managing the operating system's environment.