Animated graphic images are a series of images shown one by one in such a way as to give the impression of motion. If you create a loop in the animated graphic to repeat the series, your animated graphic can move virtually forever or run a certain sequence and stop.
Use motion graphics to help say your message. Animated graphics can make some really cool effects. It can also help convey ideas. If "a picture is worth a thousand words," just think what a well made animated graphic can say!
If you are trying to convey a procedure, animation can show that procedure. You can also show a sequence of events using animation. In this case, each picture does not need to flow smoothly visually, but can still flow smoothly with an idea.
If you are looking for a free animated graphic, there are a couple of approaches open. You can go to the search engines and look. There are tons of pictures out there, but many have copyright restrictions. You could pay the author or find pictures without restrictions.
Another approach (I think better), is to make your own free animated graphic. This does take a little bit of artistic ability, but isn't as difficult as it might seem.
If you want to make a high quality animated graphic, you need a high quality animation program. The best animation programs allow you to edit each picture. They also let you view the animations in motion as you go.
A good animation shop is worth a thousand pictures. NEW! Corel PaintShop Pro 2018 Ultimate includes an Animation Shop which does an excellent job of producing animated graphic images.