1. ls - Lists the contents of the current directory. You can use different options with this command to display specific information about the files and directories in the current directory. For example, ls -l will display the file permissions, ownership, size, and modification time of each file in the directory.

  2. cd - Changes the current working directory to the directory specified. You can specify the directory name or use a relative or absolute path to navigate to a different directory. For example, cd /home/user/Documents will change the current directory to the Documents directory in the user's home directory.

  3. pwd - Prints the current working directory. This command is useful for verifying which directory you are currently working in.

  4. mkdir - Creates a new directory. You can specify the name of the directory to create or use a relative or absolute path to create a directory in a specific location. For example, mkdir new_directory will create a new directory called "new_directory" in the current working directory.

  5. rmdir - Removes an empty directory. You can specify the name of the directory to remove or use a relative or absolute path to remove a directory in a specific location. Note that this command can only remove empty directories - if a directory contains files or subdirectories, you will need to use the rm command to remove them first.

  6. rm - Removes a file. You can specify the name of the file to remove or use a relative or absolute path to remove a file in a specific location. Note that this command will permanently delete the file, so use it with caution.

  7. cat - Displays the contents of a file on the terminal. You can use this command to view the contents of text files.

  8. head - Displays the first few lines of a file. You can specify the number of lines to display with the -n option. For example, head -n 10 file.txt will display the first 10 lines of the file.txt file.

  9. tail - Displays the last few lines of a file. You can specify the number of lines to display with the -n option. For example, tail -n 10 file.txt will display the last 10 lines of the file.txt file.

  10. cp - Copies files or directories. You can specify the source file or directory and the destination directory to copy the files to. For example, cp file.txt /home/user/Documents will copy the file.txt file to the Documents directory in the user's home directory.

  11. mv - Moves or renames files or directories. You can specify the source file or directory and the destination directory or new file name to move or rename the files. For example, mv file.txt new_name.txt will rename the file.txt file to new_name.txt.

  12. grep - Searches for text in files. You can specify the text to search for and the files to search in. For example, grep "hello" file.txt will search for the word "hello" in the file.txt file.

  13. chmod - Changes the permissions of a file or directory. You can specify the permissions to set using numbers or letters. For example, chmod 755 file.txt will set the permissions of the file.txt file to read, write, and execute for the owner and read and execute for others.

  14. sudo - Runs a command with administrative privileges. You can use this command to perform actions that require root or administrator access. For example, sudo apt-get update will update the package manager on a Linux system.