I need to track any changes in certain web pages (1000+ unique URLs).
How can I add such component to my .NET code? I know there are external free programs doing it that send email whenever there is a change but I need to include that kind of component into my existing .NET application (and I do not want email notification -> instead the program should do some web page scraping and extract the new information whenever there is a change in any of those web pages).

The frequency need to be approx. one check per day per page.

Are they any examples of how to do it?