CPC: Cost Per Click
CPC is the first of many "cost-per" metrics; cost per click is one of the most commonly used metrics. It means the average price of a single click on an ad in your campaign.
Depending on the number of competitors in your industry, the CPC can be higher or lower.
Here's an example of expensive keywords on Google Ads:
CTR: Click-Through Rate
Click-through rate (CTR) measures how often people click your ad after it's shown to them, which can help you understand the effectiveness of your ad.
CTR is calculated by dividing the number of clicks your ad receives by the number of times your ad is shown. If you have 5 clicks and 1000 impressions, then your CTR is 0.5%.
An impression is counted each time your ad is served. Impressions help you understand how often your ad is being seen.
Search Top Impression
Search top impression rate is the percent of your impressions that are shown anywhere above the organic search results.
Use this metric to see whether changes in performance are due to changes in your ads' location. This metric does not include data from Search Partners.