Resolution
Number of pixels per unit of physical length (ex: pixels per inch, or ppi)
Pixel dimensions
Number of pixels along width x number of pixels along height; affects file size & upload/download time
High resolution
Image with ppi > 200
Extras
Selection edges, guidelines, and other visual items that aren’t actually objects
Transformations
Changing the position, size, or angle of layers
Global Light
When selected, provides one “master” lighting angle for all layer effects that use shading