It is a combination of 2 words : Google and Dorking
Google: It is the very famous search engine
Dorking: Dorking means a specific search query which yields you some specific information.
Google Dorking is basically a search string that uses search queries to find information that are easily available on the websites.
How does Google Dorking Work?
Search engines crawl the Internet and index page titles, link data, and page contents, and store the data in a way in a centralized location that is optimal for satisfying search queries.
1.intitle:
As the name says it all, the search term should match the title in your browser.
2. inurl:
In the url please, It basically Searches for specified term in the URL. For example: inurl:login.php
3. filetype:
Searches for specific file type. Example: filetype:pptx will search for all the pptx files in the websites.
4. intext:
Intext as name says, in the text of the web page of a website. Eg: intext:cars will give pages which have cars in their text.
5. site:
Which site results you wish to see for specific site only. Example: site:hacktify.in will only limit the results to hacktify.in
6. Cache:
This will show you cached version of any website. Example: cache:hacktify.in
8. *
Star is also known as wildcards. Example: How to * learn hacking, will show you all the results like “how to…” easily/quickly/, etc… “sites”