101.

CSS Transitions

CSS Transition illustrated A day and night illustration of a desert landscape. Default it "day", orange and dark pink colors, with a sun high in the sky and cactuses. When you hover it, it turns into night dark purple colors, the sun sets and the moon rises.

Change one (or many) properties between 2 states, from A to B on a specific CSS trigger (hover/touch the illustration).

102.

CSS Animations

CSS Animations illustrated An little earth illustration with a little moon orbiting around it, the whole itself orbiting around a yellow pusling sun.

Change one (or many) properties between many different states and build loops using keyframes.