Fit types help us adjust how an image or video will fit in its container on the Canvas - the container being the area that a selected media's resize box occupies.
To adjust the fit type of a media, first, select it, then click on the Fit Type option on top, and we get four fit types on the left panel:
Fit with Blur option will fill the blank area of a media container with a blur.
Fit with Transparent will leave the blank area as is, and is also used to remove other Fit types.
Crop to Screen will crop the media to fill its container.
Stretch to Screen will stretch the media to fill its container.
We can also adjust the media placement after selecting a fit type using the arrow options below.