When someone clicks your ad, like on the blue headline of a text ad, Google Ads counts that as a click.

• A click is counted even if the person doesn't reach your website, maybe because it's temporarily unavailable. As a result, you might see a difference between the number of clicks on your ad and the number of visits to your website.
• Clicks can help you understand how well your ad is appealing to people who see it. Relevant, highly-targeted ads are more likely to receive clicks.
• In your account statistics, you'll see the clickthrough rate (CTR), which tells you how many people who’ve seen your ad end up clicking on it. This metric can help you gauge how enticing your ad is and how closely it matches your keywords and other targeting settings.
• Note that a good CTR is relative to what you're advertising and on which networks. To help increase your clicks and CTR, start by creating great ad text and strong keywords to make ads that are highly relevant and very compelling to your customers.

More about industry standards for measuring clicks
More about issues with clicks and clickthrough rates

* Nguồn: Google