SEO is the practice of optimizing your website to rank higher in search results and achieve better discoverability. SEA, which stands for Search Engine Advertising, is the practice of buying ads on search engines like Google to advertise your website.
Both SEO and SEA (paid ads) can help increase traffic to your website, but they differ in how they accomplish this goal.
SEO involves modifying your website to make it more attractive to search engines and better findability, while SEA involves paying money to appear at the top of the results pages when someone searches for keywords related to your business or industry.