Competitors are websites that are deemed similar to the analyzed domain and websites that compete with the analyzed domain over the same keywords.
The Competitors section contains insights on:
Similar Sites: Domains that are considered similar to the analyzed domain based on Similarweb’s similarity algorithm.
Keyword Competitors: Domains that receive traffic from the same search terms as the analyzed domain.
When comparing websites, you have the ability to toggle between each site listed in compare mode to see the list of competitors based on a site level or through organic and paid competition.
This will help you understand additional competitors based on site structure and similarities or based on search traffic -- identifying competitors for both paid or organic traffic.