Optimising your website for keywords contained in your AdWords Campaigns will increase your quality score for those keywords/search terms which reduces the cost per click and increases your ad position.
Higher ad positions allow you to display more ad features such as callouts for offers or sitelinks for additional URLs.
AdWords Search Terms feature collects all the phrases used that triggered your ads – this information is a gold mine when applied to improving your content, SEO and Ad copy.
Making your presence in the search engine results page (SERPs) more dominant with the use of AdWords and SEO not only increases traffic but also builds trust with your audience which can help your conversion rates.