Uploading videos to my course - is the limit really 8 mb?

I'm new to this game, but in putting together a 'pretend' course to see how it works the 30 second sample wildlife video was 25 mb, and my own short practice recordings of several minutes, they are 18mb ish. In some sections of my course I will be looking at videos of probably up to about 20 minutes. What do I do.