The Complete File Format Glossary — PDF, DOCX, XLSX, JPG, PNG, MP4 and More

PDF, DOCX, XLSX, JPG, PNG, WebP, MP3, MP4, WAV, AVI — the list of file formats is endless, and it is easy to get confused. This glossary explains every common format in plain English, what it is used for, and when to convert it.

Document Formats

• PDF — Portable Document Format. Read-only, looks the same everywhere. Use for sharing final documents.
• DOCX — Microsoft Word document. Editable, supports rich formatting. Use for documents you still need to edit.
• DOC — older Word format, predecessor to DOCX. Convert to DOCX or PDF for compatibility.
• XLSX — Microsoft Excel spreadsheet. Supports formulas, charts, and multiple sheets.
• CSV — comma-separated values. Plain text data, no formatting. Use for data transfer between systems.

Image Formats

• JPG / JPEG — lossy compression, best for photos, no transparency.
• PNG — lossless, supports transparency, best for graphics and logos.
• WebP — modern format, small files, supports transparency, best for web.
• GIF — supports animation, limited to 256 colors.

Audio Formats

• MP3 — universal, compressed, plays everywhere.
• WAV — uncompressed, lossless, large files.
• M4A / AAC — Apple's format, efficient, less universal.
• FLAC — lossless compression, not supported by Apple.

Video Formats

• MP4 — the universal standard, plays on every device.
• AVI — older format, less compatible, often larger.
• MKV — high-quality but not universally supported.
• MOV — Apple's format, best on Apple devices.
• WEBM — optimized for web streaming.