A format is a set of tradeoffs, not a three-letter label. Learn to choose one by what must survive the trip. Answering this file formats question well means looking at evidence from the source file, the properties covered below, and what the final destination actually requires.
Inspect signatures, MIME type, container structure, and the receiving application's documented support. The starting point for “The field guide to file formats” is this observation: Containers can hold streams, metadata, fonts, or multiple pages; extensions only hint at the internal structure.
Three findings that guide this choice
The core distinction
Containers can hold streams, metadata, fonts, or multiple pages; extensions only hint at the internal structure.
The practical trade-off
Choose an archival master before choosing a delivery copy.
The verification test
Compatibility, editability, fidelity, and size rarely peak in the same format.
A practical decision for this workflow
Keep the richest practical master, then create smaller delivery derivatives for each channel.
Use compatibility, editability, fidelity, and size rarely peak in the same format. as the acceptance test on a representative source before committing an entire archive, publication, or delivery batch.
The file formats mistake to avoid here
Renaming an extension does not convert the bytes and often leaves receiving software unable to identify the file.
That failure conflicts directly with the recommendation for “The field guide to file formats”: Keep the richest practical master, then create smaller delivery derivatives for each channel.
Review checklist before delivery
- ✓The file signature agrees with the extension.
- ✓The receiving app supports the container and internal encoding.
- ✓Required metadata or embedded resources remain present.
- ✓A richer master is stored separately from the delivery copy.
Judge “The field guide to file formats” by whether the result passes these specific checks, not by whether a new file merely opens.