One file instead of a folder of images
A dozen loose PNG files is an awkward thing to send. They arrive in whatever order the mail client feels like, they cannot be paginated, and nobody can sign them. A PDF fixes the order, prints predictably, and is the format every office process already expects.
Each image keeps its own aspect ratio and is placed on a page sized to fit it, so nothing is cropped or stretched. Resolution is preserved rather than resampled, which is what keeps screenshots of text readable instead of soft.
Common uses
- Screenshot walkthroughs collected into one document.
- Scanned pages saved as PNG and reassembled in order.
- Design mockups sent to a client as a single reviewable file.
- Receipts and proof attached to an expense claim.
Once it is a PDF you can sign it, merge it with other documents, or compress it if the images push it past an attachment limit. To go the other way, PDF to PNG exports pages as images again.