A website that helps you find information on the internet by typing keywords. Like a librarian who can instantly find any book or information you need.
Google, Bing, and Yahoo are search engines that help you find websites, images, and answers to questions.
A search engine is typically a public web service (like Google or Bing), not a single cloud provider product. Cloud providers do offer search technologies you can build into apps (for example, managed search for your own website or app), but those are not the same as an internet-wide search engine.