Your camera’s light meter measures the intensity (brightness) of light. Nothing more, nothing less.
This measurement of light is expressed as an exposure. An exposure is expressed in terms of a combination of aperture, shutter speed and ISO.
If you are working your camera in an auto mode, your camera picks an exposure for you and your composition, in terms of exposure, is limited by the camera.
If you are working your camera in manual mode, YOU pick an exposure and your composition, in terms of exposure, is limited by your imagination.