(Multi)(Default setting):

Divides into multiple regions and measures each region. The camera determines a well-balanced exposure (Multi-pattern metering).

(Center):

Measures the center of the image, and determines exposure based on the brightness of the subject there (Center-weighted metering).

(Spot):

Align the spot metering cross hairs (A) on the subject to meter one part of the subject (Spot metering). This function is useful when the subject is backlit or when there is strong contrast between the subject and background.