Great question! Both use search engines and bring people to your website, but in different ways. This is probably best explained with an example. Let’s say you search for the term “Corporate Housing.” You will get many results, some are search ads, and some are organically populated because that website had a lot of rich, engaging content that is relevant to the term “Corporate Housing.”
The search ad will be at the top, and it will have the word “Sponsored” above it.
The organic result will likely be further down, but still within the first 10-20 search results. Both are great ways to increase web traffic, but ads tend to provide more immediate results than SEO. SEO is part of playing the long game, where ads are part of the immediate play. If your SEO efforts are successful and you can rank in the first couple search results, you may eventually be able to have SEO replace your search ads.