What does the term "impressions" refer to in the context of advertising?

In the context of advertising, the term "impressions" specifically refers to the number of times an advertisement is viewed. This metric is crucial for understanding the reach and visibility of an ad campaign, as it represents each instance in which an advertisement is displayed to users, regardless of whether they interact with it or not. Impressions help marketers assess how effectively their advertising is being seen by the intended audience.

While the other options may be relevant in the broader context of measuring advertising effectiveness, they denote different concepts. Engagement scores measure how users interact with the ad, response rates pertain to the percentage of viewers who take a specific action, and total clicks indicate how many users clicked on the advertisement. None of these metrics directly equate to the definition of impressions, which solely focuses on the action of viewing the ad rather than any subsequent engagement or interaction.