The best way to learn something is watching it. Teachers have to illustrate our explanations for students to better understand the contents. On this website we can find free images that we use in our classes without copyright problems.
While this site is not for stock photos, it contains an amazing number of patterns and textures that would be great for design projects. From bold to simple, this is a texture here for almost any background. The design options here are rather broad and downloading high-resolution files takes only one-click.