What CTR tells you
Click-through rate (CTR) is clicks divided by impressions: how many people who saw your result clicked it. It depends heavily on position: the first result typically gets around a quarter of the clicks, while results on page two get very few.
Comparing your CTR with what's typical for your position shows whether the problem is your ranking or your snippet. A low CTR at a good position usually means the title and description don't match what people want.
Where to find the numbers
In Google Search Console, open Performance, click the page or search term, and turn on Average CTR and Average position. Use a few weeks of data so the numbers are stable.
A guide, not a rule
Typical rates are industry averages. Ads, AI overviews, maps, videos and brand searches all change real click rates, so use this to spot outliers, not as an exact target.