What does each metric mean?

Spend: The amount of money spent on clicks on your ads during the time frame selected

Sales: The product sales from orders within 7 days of a click on an ad if that click was made during the time frame selected. 

ACoS (Advertising Cost of Sales): Spend divided by Sales. You can look at this as how much you have to spend on ads per sale.

Impressions: The number of times Amazon shoppers saw your ad during the time frame selected, whether they clicked or not.

Clicks: How many times users clicked on your ads during the time frame selected

CTR (Click Through Rate): The number of clicks divided by the number of impressions.

Orders: The number of orders made by users after clicking your ad. Orders are counted if purchase is made within 7 days of the ad click. 

Conversion Rate: Orders divided by Clicks