Codecs are complicated. They're also an extremely important aspect of image quality, so having a basic understanding of how they work can be beneficial.
Unfortunately, for young and old filmmakers alike, trying to unravel and decipher some of the engineering concepts behind how video encoding actually works can be a bit like trying to paint a barn with a toothbrush. Complex questions abound. What is a codec – and how does it differ from a container? Bit depth: what does it mean, how does it differ from bit rate, and why is it so important? What on earth are chroma subsampling, spatial compression, and temporal compression? If you're like me, trying to wrap your head around these broad concepts, let alone figuring out the answers to the above questions, is enough to make you want to pull some hair out.
Luckily, David Kong has new video tutorial that will explain all of these things and then some (courtesy of Philip Bloom):
So there you have it, an in-depth look at how codecs work and at the inner workings of video compression. Armed with this knowledge, you can make more informed choices about not only the cameras and settings that you shoot with, but also the post-production workflows and encode settings that will give you the image quality that you're after.