Difference between Web Crawling and Web Scraping - StableProxy

Concepts of Web Crawling and Web Scraping

In this article, we will discuss the advantages and differences between the web crawling and web scraping approaches. You will learn about their application in collecting data from websites, as well as areas where they are used most effectively.

We are going to explore the difference between two methods for analyzing information obtained from various sources on the internet (specifically, websites). We will consider in detail the application and advantages of each, as well as their limitations.

What is Web Scraping?

Web Scraping is a process in which information from websites and internet resources is extracted and transformed into a format that is convenient to use.

It should be noted that modern information systems can work with different data formats. In addition to the Internet, information can be stored in local files. Offline parsers or scrapers are used to process these files.

What is Web Crawling?

The word Crawling comes from English and translates as "crawling". In the context of the web, this word is usually translated as "traversal" or "scanning". It should be noted that the word "crawler" is associated with insects crawling on the ground. In Russian, it's called a "crawler", "spider", "search robot," or just "bot". Probably, the "spider" best reflects associations with the Internet, perceived as a web where the "spider" moves along the "threads".

Web Crawling is a special script that browses sites looking for new content or changes. This process is also often called indexing by webmasters.

What does Scraping (or parsing) data mean?

There are cases where information is stored in a difficult-to-process format. For example, a complicated web address written on a paper business card. To visit the site, the client would have to manually enter all characters, which can lead to errors.

However, the process can be simplified by adding a QR code or NFC tag to the business card. Then the information can be read with a specialized application, which will eliminate errors and speed up the data-entry process.

A similar situation can arise when necessary data on a computer's hard drive is stored in an unreadable format, that is, in a format that the program cannot handle.

Another example: suppose we need to collect a database of email addresses located in various sources (in PDF, in images, in mail clients, business documents, etc.). How can all this information be aggregated in one place in such a way as to make it more readable?

In such cases, a scraper or parser can help. It's a program that can open files of different formats, find the necessary information in them, and save it in another format that's more convenient for processing. Usually, these are tables or lists, but other formats can be used (for example, XML markup).

The process of finding information and transforming it into a new view or format is called parsing or scraping.

So, scraping (or Web Scraping) is a process of discovering and transforming data into a format more convenient for use, storage, analysis, indexing, and other purposes.

Why has web scraping become so popular?

Web scraping allows for extensive site checks for errors, content quality, and structure, and also provides the opportunity to check the presence of necessary meta tags, doing so quickly and efficiently. Web scrapers can simulate user actions, which is useful for assessing website functionality and security, as well as measuring load and other characteristics.

Scrapers enable quick search for information on a chosen topic on the Internet or on specific websites. These tools also help organize and store a variety of data about competitors, for example, prices, item positions, special offers, and other important details. It's a powerful tool for conducting marketing research.

Scrapers are capable of tracking new content and reporting about various events, including negative reviews, new comments, special offers, and mentions.

With the help of special software modules, web scrapers can transform data from one format to another, for example, performing text recognition on images.

Web scrapers can operate as separate software on the user's device (on his PC or on a virtual/specialized server), or be deployed in a cloud storage and presented as a service, for example, in SaaS or PaaS formats. In some cases, web scrapers can be integrated into more complex software systems as one of the system's components.

The objectives and tasks of web scraping can be diverse, up to positive ones aimed at creating and improving, and negative ones related to industrial espionage, identifying security threats, and other purposes.

Most important tasks for business:

1. Price and competitor tracking: Scrapers are used to track prices of competitor's goods and services, allowing companies to align their prices and pricing strategies.
2. Customer and consumer data collection: Web scraping helps gather data about customers and their preferences, allowing for more precise adjustment of marketing strategies and services.
3. Reputation and feedback tracking: Scrapers are used for monitoring customer reviews and opinions about the company, helping manage reputation and improve service quality.
4. Product and assortment data collection: Companies can use scrapers to collect information about market products and services, as well as for comparative analysis of competitors' product range.
5. Potential client search: Web scraping helps identify potential clients based on their interests and online behavior.
6. Market and trend analysis: Data collected via scrapers allow business to analyze current market trends and predict future changes.
7. News and events monitoring: Web scraping allows companies to keep track of news and events in their industry, which may be useful for making strategic decisions.

Product and service comparison: Companies can compare their products and services to those offered by the competitors, to improve their offerings.

Web scraping provides businesses with valuable data and understanding that helps them make informed decisions and stay competitive in the market.

Benefits of Using Web Scraping:

Data Transformation

Web scrapers facilitate the process of translating data from one format to another, aiding in the execution of diverse tasks.

Efficient Search and Organization of Information

Scrapers simplify and speed up the process of searching and structuring the required information, making it easier to perform data analysis or monitor them.

Automation of Marketing

Scrapers facilitate the automation of a number of marketing functions, thereby enhancing the overall effectiveness of marketing campaigns.

Data Recognition and Analytics

Scrapers reduce the presence of the human factor, contributing to more precise and faster recognition and analysis of data.

Cost Reduction

Web Scraping reduces costs by actively collecting data and automating business processes.

Ability to Rent Specialized Services

Use of profile services allows for market information in ready-made form and eases the process of storing information, providing cloud solutions.

Processing Large Amounts of Data

Web Scraping allows for simultaneous processing of large data sets and working with large-scale databases.

Disadvantages of Using Web Scraping:

Excessive Load on Servers

Web Scraping can cause additional load on the servers of websites, which can lead to problems. For this reason, many large sites use various forms of protection such as bot protection systems or IP address blocking.

Need for Stable Internet Connection

Effective processing of large volumes of data requires a constant, fast internet connection. This also calls for the ability to perform tasks in parallel and use proxy server rotation to prevent IP address blocking.

Software Costs

Often, to work with powerful and flexible scrapers, it is necessary to purchase a license as free versions may have certain limitations or fail to cope with certain tasks.

Cloud Service Costs

The use of cloud services for scraping is also associated with subscription costs, which can become quite costly when dealing with large volumes of data.

Need for Data Storage

Collected data, especially in large volumes, requires additional disk space, which can take up gigabytes or even terabytes of disk space.

Specificity of Scrapers

Some scrapers may be targeted towards specific tasks, and adapting them to others can be challenging.

Complexity of Configuration

Universal scrapers may require complex setup and special skills for correct operation.

Potential Legal Issues

In the process of web scraping, one might encounter problems related to copyright infringement and data protection laws, which could result in legal consequences.

The Sequence of the Crawling Process:

• A web robot or crawler type tool reads the content of a web page.
• The extracted data, including all the HTML structure and the code of the page, is sent to the search engine server for analysis and comparison with the previous actual version.
• Alongside the analysis, an evaluation of the relevance and value of the content is conducted, different features like navigation convenience and page load time are also checked.
• If necessary, the knowledge graph or database is updated, and new pages may appear in the search results, and old or outdated content may be removed.

With basic scraping, similar steps are performed when data is collected from a web page using specialized scripts. However, in this case, the retrieved data isn't sent to and stored on the search engine servers but is saved either on the servers or on the user's computers.

So, let's clarify the main questions:

Web crawling is a process in which all the pages of a specific website are reviewed for their significance in the context of a corresponding search. The task set before search robots is to "understand" and "study" the content of each page, similar to how regular users do.

Contrary to the potentially excessive traffic that can be associated with the scraping process, crawling is a very useful action for a website. The results of crawling can lead to the website being included in search results or improve its positions if it is already in the output.

To facilitate the work of crawlers, website owners can provide special configurations and sitemaps. Using tools like robots.txt, XML maps, and unique HTML tags, webmasters can specify which parts of the website should be analyzed and which ones should be skipped, as well as ensure notification about the appearance or disappearance of materials and much more.

The difference between scraping and crawling is:

Scraping is a method of obtaining specific data from web pages, such as text, images, links, and others. It is usually used for analysis, storage, or processing of this informational data for specific purposes.

Web crawling is a general process in which a search robot or crawler goes through all the content of the website pages to assess their importance for the search. This process serves for the ranking of websites and their inclusion in the list of search engine results.

As can be inferred from the description, scraping is mainly done by users or business owners for their needs. It is used for searching, analyzing, extracting, and converting content into a convenient format.

Scraping goals are typically related to business tasks. For this, specialized software and tools are used that allow circumventing sites, circumventing blockages, and speeding up processes, for example, through rotating proxies.

On the other hand, the main goal of web crawling is indexing and search addition. Website owners do not hinder the crawling process and prepare their sites for it. Search robots are not blocked, but rather, they are awaited for obtaining new information.

With scraping, data is collected and processed according to search criteria, for example, contact information, comments, or brand mentions. This data can be exported and saved conveniently for further analysis.

In the case of crawling, data is processed only by search engines and is not provided to third parties.

The technical differences between scraping and crawling are not always clear. Any scraper can mimic a search robot or web browser and collect data in HTML code format.

The difference lies in the purpose of data processing and the technical methods used for this. Search robots don't need to get around blockages or apply additional protective measures as their work is welcomed. Unlike a scraper, which has to overcome obstacles to collect information from sites, despite possible restrictions.

Conclusion

In essence, the concept of "Web Crawling" (or simply Crawling) refers to the indexing of the content of internet pages, which is aimed at website owners, so that the information on their resources can be present in the results of organic search.

The phrase "Scraping" is not as widely spread, and it is often replaced with the term "parsing". The implementation of parsing is usually tied to commercial activities and tasks such as tracking analysis, detection, and extraction of data.

It is important to note that the technical methods of scanning and parsing have a lot in common. Both methods involve the collection and study of the HTML code of web resources.

If you are particularly attracted to data parsing (scraping), its implementation often requires more effort and resources. Even when using specialized software tools, it often requires the connection of a list of proxy servers to avoid IP address blocking and to ensure free visits to target resources.