1. ls – List directory contents
2. cd – Change directory
3. mv – Move or rename files or directories
4. cp – Copy files or directories
5. rm – Remove files or directories
6. mkdir – Create directories
7. cat – Display contents of a file
8. grep – Search for patterns in files
9. chmod – Change file permissions
10. chown – Change file ownership
11. find – Search for files in a directory hierarchy
12. top – Display processes
13. ps – Display processes
14. kill – Send a signal to a process
15. ifconfig – Configure network interfaces
16. ping – Test network connectivity
17. ssh – Secure remote login
18. tar – Create and extract archives
19. gzip – Compress or decompress files
20. nano – Text editor
21. vi – Text editor
22. df – Check disk space
23. du – Check disk usage
24. sort – Sort lines of text
25. uniq – Remove duplicate lines from a file