A photo perfect on-screen can disappoint in print — screens and paper render color and light differently.
Color profiles (sRGB, Adobe RGB, ProPhoto RGB) define the range of colors a file can represent. sRGB suits web display; wider spaces suit print, but only if your entire workflow — camera, software, printer — stays consistent. Mismatched profiles at any stage are a common cause of prints looking different from the screen.
Resolution and print size depend on pixels-per-inch at final size, not total megapixels. 300 PPI is a solid standard for close-viewing prints; larger prints viewed from further away can use lower PPI without perceptible loss.
Soft-proofing simulates how an image will look on a specific paper/printer combination before you print — catching color or contrast issues while they're still easy to fix.
Paper choice affects the image itself: glossy paper reproduces higher contrast and saturation; matte renders softer, lower-contrast tones. Worth factoring into your editing decisions when you know a specific image is destined for print.