PDF Glossary

Simple explanations of common PDF and image terms. Learn about formats, compression, encryption, and more.

• What Is PDF? (Portable Document Format)
• What Is PDF Encryption?
• What Is PDF Compression?
• Lossless vs Lossy Compression
• What Is OCR? (Optical Character Recognition)
• What Is PDF Metadata?
• PDF Permissions Explained
• What Is RC4 Encryption in PDFs?
• What Is AES Encryption in PDFs?
• What Is a PDF Watermark?
• What Is DPI? (Dots Per Inch)
• JPEG vs PNG, Which Format to Use?
• What Is WebP? Image Format Explained
• PDF Page Rotation Explained
• What Is a Digital Signature in PDFs?