Resolution on screen and in print
For screens, resolution is simply the pixel grid: a 3,000 by 2,000 image holds six million pixels and can display more detail than a 1,000 by 667 version of the same scene.
For print, density joins the picture. Pixels per inch, often discussed alongside dots per inch, describes how tightly those pixels are packed onto paper, which decides how large a picture can be printed before it softens.
Why resolution drives file size
File size scales with pixel count. Doubling both dimensions multiplies the pixel total by four, and the stored data grows in step unless compression removes something.
This is why the same photo can be 8 MB straight from a camera and 200 KB on a web page. The page version has fewer pixels and heavier compression, and at display size the difference is hard to see. Displays rarely show every level a file can store, either, so added depth mainly benefits editing rather than viewing.
- More pixels mean more detail and a larger file
- Display size sets the resolution you actually need
- Print needs higher density than on-screen viewing
- Reducing resolution is the fastest way to shrink a file
Setting the right resolution
Match the image to where it will be shown. Web images rarely need more pixels than the widest place they will appear, and larger copies only slow loading and risk upload limits.
Filekind resize and compress tools work in the browser under the limits of 16,000 pixels per side and 48 megapixels, so oversized camera files are still within reach for everyday edits.