Ad Spend Revenue
Avg. Position
The ratio between advertising spend and the revenue generated. It measures the same ratio as a Return on Investment (ROI) but displays it as a margin rather than an integer.
There are many places your ad can appear after someone has searched for your keyword. Google typically reserves the top three ads for the very top of the page, just below the search bar. For positions any lower than that your ad will most likely appear down the right-hand side of the screen or even on the second or third pages of the search results.
Ad Group Ad groups come right below campaigns in the organisational structure of AdWords. These allow for an even further distinction between your products and, as the name suggests, these are where the ads you write are stored! You only need one ad per ad group, but good practice suggests having at least two so you can compare the performance of different types of ad copy.