Algorithm, Search & Distribution
Autocomplete
Also called: search suggest, autosuggest, search predictions
Start typing a topic into YouTube's search box and it finishes the query for you in several directions at once. Creators mine that list for phrasing, because the words an audience types tend to be blunter than the words a creator reaches for.
Take it as directional. Suggestions carry no volume figure and are shaped partly by whoever is typing, so the same stem can produce different lists on two machines, which makes autocomplete good for angles and weak as evidence.