What is a "Citation Image" and "Full Text" format?

What is "Citation Image" and "Full Text" format in Ancestry® Library Edition usage reports?

A citation image is any citation, result preview, or original image. For example, a census record preview is counted as a citation image format, as is the original image. Records that are citation only are also counted as a citation image.

Records listed as "View Full Context" are counted as a full text format.