How to automatically update online content?

This my first question here and I have searched for an answer thoroughly.

Search engines all offer mostly the same results and I have found out that they accomplish that by something called web indexing or web scraping.

I want to use the same principle on another type of website. So auomatically indexing results or content. Ofcourse with the original author mentioned.

Question is, how can this be done?

(I am not a programmer and English is not my native language so I hope I have explained this well)

Thank you!