How many types of search engines are available online and can we simply say that Fiverr.com has its own search engine?
There are lots of search engines but obviously the main one is Google. There probably aren’t that many types of them.
Yes you could, for it’s site. Though Fiverr have said (in a Software Engineering Daily transcript):
We didn’t build a search engine entirely from scratch, but we’re leveraging solar
and elastic and using them in a way that is slightly different than other companies.
So they probably are using Solr search and Elasticsearch.