1. ls - List directory contents

2. cd - Change the current directory

3. pwd - Print the current working directory

4. mkdir - Create a new directory

5. rmdir - Remove a directory

6. touch - Create an empty file

7. rm - Remove files or directories

8. cp - Copy files and directories

9. mv - Move or rename files and directories

10. cat - Concatenate and display file content

11. less - View file content one screen at a time

12. head - Display the beginning of a file

13. tail - Display the end of a file

14. grep - Search for patterns in files

15. find - Search for files and directories

16. tar - Archive files

17. gzip - Compress files

18. gunzip - Decompress files

19. df - Report file system disk space usage

20. du - Estimate file space usage

21. ps - Report a snapshot of the current processes

22. top - Display Linux processes

23. kill - Terminate processes

24. chmod - Change file permissions

25. chown - Change file owner and group

26. sudo - Execute a command as the superuser

27. su - Switch user or become superuser

28. passwd - Change user password

29. ifconfig - Configure network interfaces

30. ping - Test a network connection