Google Auction is the process that happens with each Google search to decide which ads, if any at all will appear for that specific search and in which order. Each time an ad is eligible to appear for a search, it goes through the ad auction. The auction determines whether or not the ad actually shows and in which ad position it will show on the page.
The Google Auction works by Google rewarding the best message, targeting, and relevant landing page experience. That means if the searcher found what they were looking for more often with your page and ad, Google will show your ad over a competitor even if they are willing to spend more. The most important thing to remember is that even if your competition bids higher than you, you can still win a higher position (at a lower price) with highly relevant keywords and ads.
Since the auction process is repeated for every search on Google, each auction can have potentially different results depending on the competition at that moment. Therefore it’s normal for you to see some fluctuation in your ad’s position on the page and in whether or not your ad shows at all.
In the end, the more people that trust Google, the more they will return to Google.
Some information was compiled from the Google Ads support page. For more information about Google ads, please visit the Google Help Center.