What each format is good for
- AI / EPS
- Fully editable vector. The ideal starting point, and what a designer will ask for.
- Excellent when exported with vectors and fonts preserved rather than flattened to an image. A PDF can contain either — the extension does not tell you which.
- SVG
- Vector, and common from web tools. Opens in every design application.
- PNG
- Raster. Usable at high resolution with transparency, but it has a ceiling and cannot be scaled past it.
- JPG
- Raster, and compressed. Fine for photographs, poor for logos — it adds artefacts around hard edges.
- A screenshot
- Capped at screen resolution by definition. Send it if it is all you have, but expect it to be rebuilt.