What is the difference between DPI and pixels?

[sbasak]

What is the difference between dot per inch and pixel?

how does these two co-relate?

Thanks.

[DiGiTaIErRoR]

The DPI is what's printed.

On a screen it's 72pixels/inch.

[sbasak]

1 DPI = 72 pixel/inch

does it depend whether screen resolution is 1024x768 or 800x600 etc.?

[Sastraxi]

No, DPI stands for Dots Per Inch.... so 72 DPI is what's on the screen... printers can go up to 1200 DPI nowadays.

[DiGiTaIErRoR]

Originally posted by sbasak
1 DPI = 72 pixel/inch

does it depend whether screen resolution is 1024x768 or 800x600 etc.?

Your monitor will have 72 DPI regardless of resolution. That is, what you see as 72 pixels will not always be an inch. But that depends on your monitor, and your resolution.

For instance, if you have a 15" monitor doing 1600x1200, 72 pixels will be much smaller than an inch, but the data stored is 72 DPI.

I run at 1024x768 on a 15 inch monitor, probably 14" viewable or so.

1024/72 = 14.2
768/72 = 10.6

but I could run 640x480 also.

640/72 = 8.8....
480/72 = 6.6...

Thus, if you printed your screen to paper, that's how big it'd be, what your screen does is squeeze or stretch those pixels, but they remain the same digitally.

Ideally, you'd want your resolution(height & width)/72 to equal your viewable screen height & width.

That would be so you maintain close to a 1:1 aspect ratio.