If you are looking to purchase a new camera, you will probably see the terms "native ISO" and "base ISO" thrown around. ISO, being one of the three fundamental exposure parameters, is a term that all photographers should understand. This great video tutorial will explain the differences between native and base ISO and the consequences each have on your photography.
Coming to you from David Bergman with Adorama TV, this helpful video tutorial will show you the differences between base and native ISO. In the days of film, ISO simply referred directly to the sensitivity of the film you were using and was easy to understand, but in the digital era, it gets a bit more nuanced. Most digital sensors actually only have one sensitivity level. When you change the ISO, what you are roughly doing is changing the amount of a post-sensor gain that is applied to the signal, unlike film, where if you changed ISO by swapping out the cartridge, you were actually directly changing the sensitivity. Practically, this distinction doesn't really affect your day-to-day work as long as you understand the consequences of raising the ISO on image quality, but it can still be quite helpful to learn more about how ISO works. Check out the video above for the full rundown from Bergman.