1. .TXT: Plain Text File
2. .DOC: Microsoft Word Document
3. .XLS: Microsoft Excel Spreadsheet
4. .PPT: Microsoft PowerPoint Presentation
5. .PDF: Portable Document Format
6. .HTML: Hypertext Markup Language
7. .XML: Extensible Markup Language
8. .JSON: JavaScript Object Notation
9. .CSV: Comma Separated Values
10. .RTF: Rich Text Format
11. .JPG: Joint Photographic Experts Group
12. .PNG: Portable Network Graphics
13. .GIF: Graphics Interchange Format
14. .TIF: Tagged Image File Format
15. .BMP: Bitmap Image File
16. .MOV: Apple QuickTime Movie
17. .MP4: MPEG-4 Video File
18. .AVI: Audio Video Interleave File
19. .WAV: Waveform Audio File
20. .MP3: MPEG-3 Audio File
21. .ZIP: Compressed File Format
