JPG and PDF explained
JPEG is a lossy image format designed for photographs. It works by discarding detail the human eye is least likely to notice, particularly in colour and in smooth gradients, which is why it compresses photos far better than it compresses text or line art.
PDF describes a page as a fixed arrangement of text, vector graphics and images. Unlike a word processor document, it is designed so the page looks identical everywhere — which is exactly why it is awkward to edit.
- Where JPG files come from
- Digital cameras, phone screenshots on Android, and essentially every photo on the pre-2015 web.
- Where PDF is used
- Contracts, invoices, reports, forms, academic papers and scanned documents.