Exposure Triangle
Exposure is the amount of light that hits your sensor.
Lots of good article. Here's one: https://photographylife.com/what-is-exposure
The exposure triangle are 3 settings that all interact to give you a "properly exposed" photo:
- Shutter speed
- Aperture
- ISO sensitivity
What's properly exposed? I guess it would be
According to this article:
https://visualwilderness.com/fieldwork/reason-change-iso-in-photography
You should just keep you ISO setting at the lowest and vary the other two settings. The article says that you should only change your ISO when you're targeting a particular shutter speed.