Canon EOS R50 Mirrorless Camera (White) - Manual (Page 214)

: Center-weighted average
The metering across the screen is averaged, with the center of the screen weighted
more heavily.
Caution
With (evaluative metering), holding down the shutter button halfway when
shooting with [ One-Shot AF ] locks the exposure value (AE lock). With (partial
metering), (spot metering), or (center-weighted average metering),
exposure is set at the moment the picture is taken (without locking the exposure
value when the shutter button is pressed halfway).
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