SEO is an organic digital marketing channel and Google/Meta ads are paid digital marketing channels. An organic channel means you don’t pay for the space.
For example, SEO services are there to optimise your website so that it shows up in Google’s search results just because it meets the standards of Google’s algorithm. Google Ads, on the other hand, are paid advertising slots on search results pages that are usually listed with a “Sponsored” disclaimer.
This works similarly for Meta’s social media platforms. Organic social media posts are the ones that naturally show up on the feed. But Meta Ads are sponsored posts on social media feeds.
Digital ads are great for quick wins with their downside being a much more expensive overhead. Whereas SEO (which also works on social media, by the way) is all about catering to the algorithms and helping your website or posts show up for free.