This is one of the most commonly asked questions marketers often get. The short answer is, it is a little more complicated than just giving the stark definitions of the two.
The majority of people worldwide use Google as their traffic source (around 73%). There are two ways to search on Google, which are known as search engine optimization (SEO or Organic Search) and search engine marking (SEM or Paid Search). For more in-depth information about these two, you can visit the following:
SEO: The Beginner’s Guide to SEO
SEM: A Beginner’s Guide to Paid Search
Now that you’ve gotten an in-depth understanding of the two, let’s look at the differences at a high level.