What these numbers are, and are not
Every figure above comes from the Search Analytics API for a property I own or manage. A service account with read-only access copies the daily rows into this site's database, and the page reads from there.
Clicks are visits from Google search results. Impressions are how many times a page appeared in results, whether or not anyone clicked. CTR is clicks divided by impressions, and average position is where the pages ranked on average, weighted by impressions. Lower is better, so a position moving down shows as an improvement.
Search traffic is not revenue, and Google only publishes a day's numbers a couple of days after it ends, which is why the window stops short of today. When a property is not connected yet, its tile says so and shows an estimate worked out from a screenshot, never a live figure.