When to use IMG vs. CSS background-image?

Answer 1

Another background-image PRO: Background-images for

/
lists.

Use background images if they are part of the overall-design and are repeated on multiple pages. Preferably in background sprite form for optimization.

Use tags for all images that are not part of the overall design, and are most likely placed once, like specific images for articles, people, and important images that deserve to be added to google images.

** The only repeated image that I enclose in a tag is the site/company logo. Because people tend to click it to go to the homepage, thus you wrap it with an tag.