When you run Google Ads (also known as PPC or pay per click ads) you are paying every time someone clicks the ad and goes through to your website. If you have the budget to do both, then taking as much real-estate on Google for high performing keywords is the best scenario. You will need to choose between the short term or long term strategy. Undertaking SEO and ranking organically means you can essentially generate free traffic to your website consistently, and that's why we love SEO. Of course, you will still need to optimise your website before the search engines start ranking you.