Answer:
This is known as: Autocomplete.
Step-by-step explanation:
Autocomplete is a feature used in many applications especially search engines to help a user predict what the user is typing.
When this is present in an application, it can help make searches faster. When a user sees a suggested Autocomplete search option, they can just go ahead to click on the suggestions or scroll down further to see more suggestions.
In the case of Joan, all she had to type was "dog walking tips" and because the search engine had Autocomplete features, it gave her a complete suggestion of "dog walking tips and tricks". That's what Autocomplete is.