Google autocomplete is algorithmically determined. As you type, Google's algorithm predicts and displays search queries based on other users' search activities. In addition, if you're signed in to your Google Account and have Web History enabled, you may see search queries from relevant searches that you've done in the past. All of the predicted queries that are shown in the drop-down list have been typed previously by Google users. Predicted queries are algorithmically determined based on a number of purely objective factors (including popularity of search terms) without human intervention. The autocomplete data is updated frequently to offer fresh and rising search queries.