The command-line interface (CLI) is a powerful tool that allows users to interact with their operating system by entering commands. These commands, also known as command-line utilities or shell commands, can be used to perform various tasks such as navigating the file system, manipulating files and directories, and controlling system processes.

There are many command-line utilities available, but some of the most commonly used ones include:

  1. cd: The 'cd' command is used to change the current working directory. For example, to navigate to the Documents directory, you would enter 'cd' Documents.
  2. ls: The 'ls' command is used to list the contents of a directory. You can use it to see the files and subdirectories within a directory. For example, to list the contents of the current directory, you would enter 'ls'.
  3. mkdir: The mkdir command is used to create a new directory. For example, to create a new directory called Project, you would enter mkdir Project.
  4. pwd: The pwd command is used to display the current working directory. This can be useful if you want to know where you are in the file system.
  5. cp: The cp command is used to copy a file or directory. For example, to copy a file called file.txt to a new location, you would enter cp file.txt /path/to/new/location.
  6. mv: The mv command is used to move or rename a file or directory. For example, to rename a file called old_name.txt to new_name.txt, you would enter mv old_name.txt new_name.txt.
  7. rm: The rm command is used to delete a file or directory. Be careful when using this command, as deleted files cannot be recovered.
  8. cat: The cat command is used to display the contents of a file. This can be useful if you want to quickly view the contents of a file without opening it in a text editor.
  9. less: The less command is similar to the cat command, but it allows you to view the contents of a file one page at a time. This can be useful if the file is very large and you don't want to scroll through the entire thing at once.
  10. grep: The grep command is used to search for a pattern in a file or files. This can be useful if you are trying to find a specific word or phrase in a large text file.