Web scraping is the process and techniques used in extracting data from a website by using a software or code.

The code created for web scrapping is known as scrapper. The scraping is done by sending a request to the targeted website which would then pass up an HTML document, and then the scrapper searches for the information required and converts it to the required format.

If you want to start building your own scraper, you might want to have a look at ProxyCrawl as for sure it will be of great help.