It’s been a long time since the last time I write about basic photography. I just stumbled upon a great article on explaining metering modes. I’ll just copy paste it from DPS because I think there’s just no need to rewrite the whole thing. It’s already basic enough.
Credits to the original author. Here goes.
On today’s digital cameras, users have the ability to choose and adjust the metering mode, or how the camera measures the brightness of the subject. Metering settings work by assessing the amount of light available for a photograph, and then adjusting the exposure accordingly. Sometimes, however, the camera isn’t intuitive enough to get the exposure right when using Program, Shutter Priority, or Aperture Priority modes. Fortunately, the photographer has the ability to make manual adjustments to the metering mode used by the camera. (Refer to your individual owner’s manual to learn how to change the settings on your camera.)