To enumerate, AdSense For Search (AFS) is a Google product that lets you enhance your website with Google Search and Shopping ads and earn additional revenue. AdSense for Search is part of the already existing AdSense family of products. You can use AdSense for Search in addition to AdSense for Content and monetize your search results pages and your website's content.
In the first place, Keyword Tool is a free online keyword research instrument that uses Google Autocomplete to generate hundreds of relevant long-tail keywords for any topic. Whereby, Google Autocomplete is a feature used in Google Search. And its purpose is to speed up the searches performed by users on Google.
With Google Callout Extensions, you can easily promote unique offers to shoppers, like free shipping or 24-hour customer service. And when customers see your ads, they get detailed information about your business, products, and services. So, these callouts can highly improve your text ads by promoting unique offers to shoppers.
Google Keyword Planner helps you research keywords for your search campaigns. You can also use this free keywords tool to discover new keywords related to your business. And even see estimates of the searches they receive and the cost to target them.