An impression is counted each time your ad is shown on a search result page or other sites. Each time your ad appears on, let’s say Google or Meta, it’s counted as one impression. In some cases, only a section of your ad may be shown.
For example, in Google Maps, your business name and location may only be shown, or your business name and the first line of your ad copy.
You’ll sometimes see the short form ”Impr” in your account showing the number of impressions for your ad.