JFIF is the abbreviation of JPEG File Interchange Format (JPEG File Interchange Format), which is a standard file format for storing and transferring images in JPEG format. The JFIF format usually uses the extension .jpg or .jpeg to represent the JFIF format defines a file header information, which includes some metadata of the JPEG image, such as the resolution of the image, color space, compression quality, etc. These Metadata can help software decode and display JPEG images correctly. It should be noted that the JFIF format itself does not define how JPEG images are encoded, but only provides a method for standardizing JPEG files when stored and transmitted. Therefore, the JFIF format can be used with a variety of compression and encoding options, such as JPEG formats based on Huffman encoding, arithmetic encoding, or lossless encoding. Overall, the JFIF format is a standardized way of storing and transferring JPEG images, making it easier to exchange JPEG image files between different systems.

PDF (Portable Document Format) is a versatile file format developed by Adobe that preserves the fonts, images, graphics, and layout of a document, regardless of the software, hardware, or operating system used to view it. It is widely used for sharing documents in a fixed layout, ensuring consistency across platforms. PDF files can be viewed on virtually any device, making it a preferred choice for documents that require secure and accurate presentation, such as eBooks, forms, manuals, and reports. PDFs also support interactive elements like hyperlinks, buttons, and forms, and can be encrypted for security.