Additionally, someone with a screen reader might be able to hear a description for a properly-tagged image, such as “cat sleeping on a windowsill” or "person riding a horse.” Similarly, image buttons can also have alt tags: for example, on a shopping site, the buy button might have “this is the buy button for PayPal” as an alt tag. Without alt tags, vision-impaired users and would not know what’s in the image and wouldn’t be able to make a purchase.