No More Confusion: Web Crawling vs. Web Scraping

    It is easy to get overwhelmed with all the jargon and terms thrown around regarding online marketing. It is equally easy to confuse one thing for the other, which can be a significant disadvantage. This is especially so for a business owner whose priority could just be to have an effective marketing campaign.

    Two terms that are often confused are web crawling and web scraping. But just what is the difference between the two? What is a web crawler? And what is a web scraper? This article will walk you through what they are, what they each entail, and where you can apply them while collecting data for your organization.

    What is Web Crawling?

    Web crawling is the process of utilizing bots to not only read but also store all content that is located on a website. Usually, this is done for indexing or archiving purposes. It is a process mainly utilized by search engines and aggregator sites. The bots discover content, extract all info hosted on a website, and index it so that when a user searches for a specific keyword, phrase, or topic, the search engine can make the most accurate result recommendations.

    The bots, in this case, are also referred to as web crawlers. 

    What is a web crawler? 

    Also referred to as a spider, crawl bot, or search engine crawler, a web crawler is an automated program that works by following links between sites and archiving or indexing them. You can find even more details about web crawlers in the article from the Oxylabs blog

    These crawlers keep a record of the pathway to a specific site, any links between pages, along with information such as photo description tags, alt tags, and meta tags. All these aid in faster retrieval of the information on the website when needed which can be integral in specific application areas, especially in business.

    Web Crawling Steps and Stages

    Web crawling comprises six main steps, also referred to as stages. This first begins with identifying the correct URLs, after which they are added to the crawl queue, which makes up the first stage of the crawling process. 

    The crawler then goes through these URLs before processing them in the third stage and forwarding them to the render queue. The HTML renderer then takes over. Once it renders the HTML code file, the data is taken through another round of processing, known as parsing, before final indexing.

    These six stages can be broken down into three main phases – crawling, rendering, and indexing.

    What is Web Scraping?

    Web scraping, on the other hand, involves extracting any publicly available data on the internet, organizing it into a structured format, and preparing it for download by saving it as a .CSV or JSON file. The now structured data can be channeled to another website or software for analysis.

    Bots known as web scrapers conduct web scraping. They are available off the shelf. Alternatively, they can be fashioned from scratch; Python is the most common language developers use to create a custom web scraper. 

    Web Scraping Steps and Stages

    Like web crawling, web scraping also comprises several steps, all of which start with identifying a target website. In this case, the user inputs the target website. Alternatively, a web crawler can be used to discover a target website or web pages. 

    Next, the scraper makes an HTTP request to the web pages via their respective URLs to get the page’s HTML code file, after which locators/parses are used to find the specific data within the file. Once the data is identified and collected, it is saved in a structured format, primarily as .CSV or JSON files.

    Difference Between Web Crawling and Web Scraping

    One of the main differences between web crawling and web scraping is that the latter extracts and duplicates the collected data for use by human users or data analysis software. Web crawling, on the other hand, does not extract the data or prepare it for download by you, the user. Instead, when prompted, it navigates and reads pages for indexing for the data to be retrieved autonomously by search engine software. 

    Secondly, web crawling archives all data indiscriminately while web scraping extracts specific, pre-defined data. Thirdly, web crawling is mainly used in large-scale data extraction efforts, while web scraping is more flexible – it can be used in small-, mid-, and large-scale applications.

    That said, when combined, both of them are extremely useful in collecting and processing data. For instance, web crawlers help discover web pages from which the scrapers extract the data. 

    Notably, web scraping is highly effective in e-commerce monitoring, market research for new products, news aggregations, and data journalism, among others. On the other hand, web crawling is particularly useful in price monitoring, collaborative research, and as a search engine optimization (SEO) analytics tool.

    Conclusion

    Web scraping and web crawling are unquestionably useful for businesses, both when used individually or collectively. When combined, they can yield incredible results that can help inform a company’s marketing decisions, pricing strategy, and reputation management, among others.