Hotlinking, direct-linking, and remote-linking are all synonyms of each other. These are all ways of taking images, or other files and embedding them directly into a website. In other words, it is an unauthorized way of using someone else’s bandwidth. Hotlinked files are not stored on your own server. Hotlinking is equivalent to theft/stealing.
If the person who owns the media file you are embedding into your own website gives permission to hotlink, then nothing is wrong. However, if you do not have the owner’s consent, then even if it is a clipart or any other simple file, hotlinking is considered stealing.