Metering: “Evaluating how much light is present.” “The camera uses this information to calculate the proper exposure…”
Evaluative: use in most situations;
“The camera uses its metering sensors to indicate where, across the entire scene, the bright and dark sports are located and then adjusts the exposure appropriately.”
Center-weighted: use when subject is backlit and you wish to expose the centered subject sufficiently.
“The camera weighs the center more heavily.” However the entire scene is metered, so a good balance between spot and evaluative.
Spot: a form of manual metering. Apparently, you can meter yourself by half-pressing the button.
”...a precise way to read a meter from the center (normally) of the frame.”