What makes Web Crawling different from Web Scraping?
Web Crawling and Web Scraping are two key methods of analysing web resources
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31 серпня 2023
Web Crawling and Web Scraping
In this article, you will learn about the pros and differences between web crawling and web scraping. Let's take a look at how these approaches are used to retrieve data from websites and get an idea of their applications.
In this article, we will take a closer look at the difference between the two approaches to the analysis of data extracted from various sources on the web (from websites). We will show when and for what purposes these methods are used and discover their advantages and limitations.
What is Web Scraping?
Web Scraping is the process of extracting and converting data from websites and online resources into a usable format.
It is important that modern information systems can process various data formats. In addition, the data is not always only on the Internet. To work with local user files, there are offline parsers or scraper programs.
What is web crawling?
Crawling is an English term meaning "crawling". In the context of websites, it is translated as "crawling" or "crawling". Interestingly, the creature "crawler" (Crawler) in English is associated with a "crawling insect". In Russian-language versions of a web crawler, it is often called a "spider", "search robot" or simply a "bot". Probably "spider" is better associated with the concept of the Internet than just "insect".
Web crawling is a special script that traverses websites in search of new content and changes. Webmasters refer to this process as indexing.
What does data scraping (or data scraping) mean?
Sometimes information is stored in a format that is not very convenient for further processing. Let's take an example: it could be a complex web address on a manager's paper business card. In this case, the client has to manually enter letters, numbers and other symbols on the keyboard to turn this address into text form and enter it into the address bar of the browser to access the corresponding website.
However, you can change this format by adding a QR code to a business card or using an NFC tag. In this case, the client can easily read the necessary information using specialized programs. This prevents possible errors and greatly speeds up the data entry process.
A similar situation arises when the necessary data stored on the hard disk of a computer is in a practically "unreadable" form, that is, in a format that is incompatible with programs. After all, any program is capable of processing only those formats that were incorporated in its development. If the formats do not meet these standards, the program will not be able to read the file correctly.
Let's look at another example: suppose you need to collect a database of email addresses, but these addresses are stored in various sources, such as PDF files, images (photos of business cards),email clients, business documents, etc. How can you combine this information in one place and at the same time turn it into a more convenient and readable format?
In such a situation, a scraper program, also known as a scraper, can help. It is able to open files of different formats, and then find the necessary information in them and save the data in a different format. This is usually in the form of tables or lists, but other formats such as XML markup, etc. can be used.
The process of discovering information and changing it into a new form or format is called parsing or scraping.
Based on the English term "scraping", meaning "scraping" or "scraping", we can formulate the following definition.
Scraping (or Web Scraping) is the process of finding and converting data into a more usable format that can be used for analysis, storage, indexing, and other purposes.
Why are web scrapers the most popular?
With the help of web scrapers, you can conduct bulk site checks for errors, content quality and structure compliance, as well as checking for mandatory labels and tags, and this can be done quickly and efficiently. Web scrapers can emulate user actions, which allows you to evaluate the performance of websites and their security, as well as measure load and other characteristics.
With the help of scrapers, you can quickly find information on a given topic on the web or on certain websites. These tools also allow you to organize and store various data about competitive sites, such as prices, assortment, promotions, and other important information. It is a massive marketing research tool.
Scrapers can track new content and report various events such as negative reviews, new comments, special offers, and mentions.
In addition, with the help of special software modules, scrapers can convert data from one format to another, for example, recognize text information in images.
Web scrapers can be used as standalone software on the user's device (on their computer or virtual/dedicated server),or they can be deployed in the cloud, provided as a service in SaaS or PaaS format. In some cases, scrapers can be included in more complex software packages as one of the system components.
The tasks and goals of web scrapers can vary widely, including both positive, aimed at creating and improving, and negative, related to industrial espionage, detection of security vulnerabilities, and other goals.
The most necessary tasks for business:
- Price and Competitor Monitoring: Scrapers are used to track the prices of competitors' goods and services, allowing companies to tailor their pricing and pricing strategies.
- Collecting customer and consumer data: Web scraping helps collect customer and benefit information, allowing you to fine-tune your marketing campaigns and services.
- Reputation and feedback monitoring: Scrapers are used to track customer feedback and opinions about the company, helping to manage reputation and improve the quality of service.
- Gathering product and at datassortmen: Businesses can use scraping to collect data about products and services in the market, as well as to analyze the assortment of competitors.
- Lead Search: With web scraping, you can identify leads based on their interests and online behavior.
- Market and trend analysis: The data collected through scraping allows businesses to analyze current market trends and predict future changes.
- News and Events Monitoring: Web scraping helps companies keep track of news and events in their field, which can be useful for making strategic decisions.
Benchmarking Products and Services: Businesses can compare their products and services with similar offerings from competitors to improve their offering.
Web scraping provides businesses with valuable data and insights that help them make informed decisions and stay competitive in the marketplace.
Benefits provided by Web Scraping:
Solving data transformation tasks
Web scrapers allow you to efficiently convert data from one format to another, which is useful for various applications.
Quick search and structuring of information
They speed up the search and organization of the data you need, which makes it easier to analyze and monitor.
Marketing Automation
Scrapers automate many marketing tasks, which helps to increase the effectiveness of marketing campaigns.
Improving accuracy and speeding up recognition
They exclude the human factor, which leads to more accurate and faster data analysis.
Resource Saving
Web Scraping reduces costs by retrieving data quickly and automating business processes.
Convenience of renting specialized services
When using a specialized service, market data can be provided in a ready-made form, as well as cloud storage for convenient storage of information.
Processing a lot of data and working with large databases
Web Scraping allows you to process a large amount of data at the same time and work with large databases.
Negative aspects when using Web Scraping:
Increased load on the target site
Web Scraping can put extra load on websites, which can cause problems for servers. Therefore, many major portals have adopted protective measures such as displaying captchas, blocking IP addresses, or customer scoring systems.
The need for a stable network connection
Efficient burning of large amounts of data requires a constant and fast network connection. It also requires task parallelization and the use of rotating proxies to avoid blocking the IP address.
Software costs
To use powerful and flexible web scrapers, you often have to buy licenses, as free versions may be limited or incompatible with specific tasks.
The cost of cloud services
Renting cloud services for scraping also requires you to pay for a subscription, which can be costly when dealing with large amounts of data.
The need for data storage
Collected data, especially in large volumes, requires additional disk space, which can require gigabytes or even terabytes of disk space.
Parser specialization
Some scrapers can be specific and difficult to adapt to different tasks.
Difficulty of setting
All-purpose scrapers can be difficult to set up and require specialist knowledge and experience to determine the correct steps and settings.
Potential violation of laws
Web scraping can violate laws, especially with respect to copyright and data protection regulations, which may result in legal consequences.
The scanning process follows the following mechanism:
- A specialized tool, such as a web bot or spider, opens the content of a web page.
- The received data, including the entire HTML structure and page code, is sent to the search engine server, where it is analyzed and compared with the previous current version.
- In parallel to the analysis, the relevance and usefulness of the content is assessed, and parameters such as ease of navigation and page load speed, among many others, are checked.
- Changes are added to the knowledge graph or database as needed, and new pages can be included in search results, while outdated or irrelevant content can be removed.
With basic scraping, similar actions are performed, where data is extracted from web pages using special scripts. However, in this case, the collected data is not sent and stored on the servers of the search engines, but is stored either on the servers or on the users' computers.
So, let's clarify the main points:
Web crawling is a process that analyzes the content of all pages on a particular website to evaluate their relevance in the context of relevant searches. The task of search bots is to "understand" and "learn" the content of each page, as normal users would.
Unlike the potentially unnecessary traffic that can be associated with the scraping process, crawling is a very useful operation for a website. Crawl results may result in the site being included in the search results or improving its position if it is already in the results.
To facilitate the work of search crawlers, website owners can provide special settings and maps. Using tools such as robots.txt, XML maps, and custom HTML tags, webmasters can specify which parts of a site to crawl and which to ignore, alert when content appears or disappears, and more.
The difference between Scraping (parsing) and Crawling is as follows:
Scraping (parsing) is the process of obtaining specific data from web pages, such as text, images, links, and other elements. It is most often performed in order to analyze, store or process this information for specific needs.
Crawling (web crawling) is a general process in which a search bot or crawler analyzes the content of all pages on a website to evaluate their relevance to search engines. This process is used to rank websites for inclusion in SERPs.
As can be understood from the description, Scraping is often performed by users or business owners for their own purposes. It is used to search, parse, extract and transform content into a usable format.
The goals of scraping (scraping) are often related to commercial tasks. For this, specialized software and tools are used to bypass blocking and speed up processes, for example, using rotating proxies.
On the other hand, the main purpose of web crawling is to index and add to search. Website owners welcome the crawling process and prepare their sites for it. Search bots are not blocked and, on the contrary, are expected to collect information.
With scraping, data is collected and processed according to search criteria such as contact information, comments, or brand mentions. This data can be exported and stored in a convenient location for further analysis.
In the case of scanning, the information is processed only by search engines and is not available to third parties.
The technical differences between scraping and scanning are not always obvious. Any parser can mimic the actions of a search bot or web browser and extract data as HTML code.
The main difference lies in the purposes of data processing and the technical methods used for this purpose. Search bots do not need to overcome blocking or apply additional security measures, as their activity is welcome. Scrapers, on the other hand, have to overcome obstacles in order to collect information from sites, despite possible limitations.
Conclusion
In general, the term "Web Crawling" (or Crawling) is associated with the process of indexing the content of web pages and is intended primarily for the owners of the websites themselves so that their information can be included in organic search results.
The word "Scraping" is less common, and the term "scraping" is more commonly used instead. The scraping process is usually associated with commercial goals and objectives, such as monitoring, analyzing, searching and deleting data.
It is important that the technical processes of scanning and parsing have much in common. Both processes involve collecting and parsing the HTML code of web pages.
If you are interested in parsing (scraping) data, this, as a rule, requires additional efforts and resources. Even when using specialized software, it is often necessary to enable proxy lists to avoid blocking the IP address and ensure unhindered access to the target sites.