Description of the resolution of Photoshop

I found some friends just touch Photoshop, for the resolution is very strange, you see this picture, what is represented, it will certainly be very blindfolded,

And then everyone knows I created a 160px*80px, resolution of 72px/inch size document, that's true, but that's not the point I'm talking about. What if I now adjust the resolution to 300px/inches? In fact, and before the same size of the document, because my document size is 160px*80px with the following resolution is not related, this is in the width and height of the pixel is the case, the attention is on the screen device side I said no difference that is no problem, But we want to print out there are some problems, if it is 72 resolution, printing size is larger, high blur, 300 resolution, print size is relatively small, high clarity, you can in Photoshop, respectively, a width and height are the same resolution of the same document, such as 160px* 80px 72 resolution, 160px*80px 300 resolution, and then go to the document in the image-"image size, to see their length units, such as cm (cm) is certainly not the same, look at this picture, width height is cm (cm), the following resolution is Work, because inches is the length of the unit, an inch is about 2.5 cm (cm), so you can mental arithmetic the size of the document to say, the width of 11.04cm about 4 points a few inches, even if 4 bar, 4*72=288px, width is about 288px, Height 5.96cm, even if 2.5 inches, 2.5*72=180, height about 180 or so, you can calculate with calculator, this is the document size is about 288px*180px; now I'm going to 300px/inches and I can calculate the width 4*300= 1200, Height 2.5*300=750

The document size is about 1200px*750px, I hope this is a bit of help for beginners ....

Description of the resolution of Photoshop