A search engine is computer software. It’s crawling the internet for web content, indexing the web content, storing the website contents, search algorithms and results.
well, though most persons already know what search engine is ,.but good that you gave some definition to it for the sake of the newbie sellers and buyers and those who don't know the definition, what you post will give an insight to it. search engine is also used to query keyword(s) either long or short for the purpose of searching out and displaying some web content in relation to the searched keywords in the search engine results.
