Web scraping is a mechanism to retrieve information from a web page. This mechanism consists of numerous tools. All of them have the objective to read the web site and return the information in a semi-structured shape, usually HTML or XHTML.
A paradigm of data mining?
It can be seen as another paradigm of data mining but it is not. Data mining reads data sets in order to perform analysis and understand trends in data.
On the other hand, web scraping is all about getting data, not to analyze them.
How is it used?
One of the most famous applications of web scraping is the crawler. The crawler, or spider, is a software. Its function is to read website information. They are usually created in order to help search engines returning more effective information to the user. One famous crawler is Googlebot from Google.
The advantage of web scraping is easy to understand. Through web scraping, in fact, search engines are able to expand their offerings. In the early years of the Internet, this process was done manually. There were people that were navigating the Internet and taking pieces of information for search engines.
As you may guess this was not an efficient way and search engines were not able to expand their search results as quickly as they can now.
SEO related aspects
This process is in the spotlight when we talk about SEO techniques. SEO is the acronym for “Search Engine Optimization“. It includes a universe of concepts and best-practices for webmasters. These concepts aim to make a website appearing in the first position of the SERP (Search Results Page).
Why is web scraping considered a SEO tecqnique?
Well, to have your website appearing in the SERP you need to create content that is using the keywords the user is looking for. The content has to be better than competitors. So one way to do that is to analyze contents from the competitors’ websites. Thus web scraping is the solution for that.
Is web scraping legal?
Let’s say that it’s a very “gray” area. There are no certain laws that are against this process. So I would say that everything is still falling on the legal side. But be careful, some search engines like google don’t like it when you use it to get to the top of the SERP.