CTR, or Click-Through Rate, is a metric used in digital marketing to measure the effectiveness of online advertising campaigns. It is calculated by dividing the number of clicks an ad receives by the number of times the ad is shown, then multiplying by 100 to get a percentage. A higher CTR indicates that more users are engaging with the ad, which can lead to better performance and return on investment. CTR is important for evaluating the success of various online platforms, including Google Ads and social media advertising. Marketers use this metric to optimize their campaigns, improve ad content, and target the right audience. Understanding CTR helps businesses make informed decisions about their advertising strategies.