A search engine helps interested people to find your web site. I ask the search engine to find everything connected with the words forensic AND science. I want to know something about the fishing industry or oil refineries or rare books. I just tell the search engine to look for the special words I am interested in.
Search engines offer two levels of search.
A basic search lets you specify one or more words to look for, but unless the words you want are very unusual, the results may not be relevant to your needs - or the relevant sites may be buried somewhere in a long list of irrelevant ones. It is possible get much more targeted results using the 'advanced search' facility which most search engines provide. There will be thousands of 'hits' in the results list, and the one you need may be at the bottom of the list. Advanced searching also lets you search using the words AND, OR, NOT and NEAR, and you can ask for the results to be ranked with the word or phrase that is most important to you coming first in the list. No, there are lots.