Photoshop has a huge array of tools and features, and many of them have a bit of overlap between their purposes and functions. Two of the most fundamental tools in the program are the opacity and fill sliders. If you have tested them out and are not quite sure of the differences between the two, check out this excellent video tutorial that will show you everything you need to know, along with a wide range of helpful examples and exercises.
[ Read More ](Originally posted by Alex Cooke)