These are split into zones, each measuring the brightness of the light from a different part of the scene. The number of zones ranges from 21 to 63, depending on the camera.
Zone metering can determine the type of lighting in the scene. If all the zones give similar readings, the lighting is probably even, perhaps with the sun behind the camera. However, if the centre zone gives a lower reading than the outer zones, it is possible that the subject is backlit.
Evaluative metering analyses the zone readings and interprets the results, adjusting the exposure readings to compensate for unusual lighting situations and then setting a suitable aperture and shutter speed to give correct exposure.
Center Weighted metering checks the whole scene, but places an emphasis on the central area – useful for landscape photography.
Partial metering takes readings from just a central area of the scene, covering up to 10% of the viewfinder frame area. This is useful when you want to obtain correct exposure for a specific area of the subject, such as the face in a portrait.