Canon EOS REBEL T8i Advanced User's Manual page 264

Note
If [–] is set for both the RAW image and JPEG image, will be set.
If you select both RAW and JPEG, each time you shoot, the image will be recorded
simultaneously to the card as both a RAW and JPEG image at your specified
image qualities. The two images will be recorded with the same file numbers (file
extension: .JPG for JPEG and .CR3 for RAW).
is in (Fine) quality.
Meaning of image quality icons: RAW, Compact RAW, JPEG, Fine,
Normal, Large, Medium, Small.
264