The blending modes play with the darkness and lightness as u can say ,
and there are 2 main sections that i usually use
1st) Darken modes (shows dark colors only)
like multiply (it shows only black and dark colors and hides white
2nd) lighten modes (shows white colors only)
like screen (which hides black and darken from the photo and appears white and lighten colors)
check this page it may help you understanding blending modes