When users search on Google, text ads may appear above or below search results.
relevant thresholds, user search context (location, device, time and search terms, other ads and search results on the page, and additional user metrics and attributes)
The thresholds for displaying search results above are generally higher than those required for displaying search results.
Be relevant: Make sure your ads and landing pages match user searches. Irrelevant ads may be shown.
Bid competitively: Bid high enough to compete with other advertisers bidding on the same keywords.