Crawling is a process where search engines or web crawlers (also known as robots or spiders)automatically browse and collect informationfrom web pages on the internet. Through this process, search engines understand and index the content of countless web pages on the internet, reflecting them in search results. Here is a detailed explanation of the concept and process of crawling.

Concept of Crawling

Web Crawler: It is a software or bot that performs crawling. The crawler accesses a specific website, follows links, collects and analyzes the content of the page.

Indexing: This is the process of storing the content of web pages collected through crawling in a search engine database. During this process, the search engine analyzes the content, metadata, keywords, and link structure of each page.

Sitemap: It is a file that describes the structure and pages of a website. Crawlers refer to sitemaps to efficiently crawl pages on a website.

Crawling Process

Starting Page: Crawlers generally start from an already known website or root domain. Crawling starts based on this page.

Link Tracking: Crawlers track links within web pages and move to other pages through those links. Crawling proceeds by following the connection relationship between web pages.

Content Collection: Crawlers collect text, images, metadata, etc. from each page. This information is stored in the search engine's index and used to generate search results.

Iteration: Crawlers continuously crawl multiple pages, discovering new links and collecting additional pages.

Crawling Examples

Google Search Engine: Google crawls the entire web to generate search results. It uses various web crawlers, and the crawled information is converted into searchable data through Google's indexing process.

Specialized Crawling : There are also crawlers specialized in specific topics or industries. For example, there is Google Scholar, which crawls academic papers, and real estate websites that crawl real estate information.

Price Comparison Websites : Crawlers collect price information from online stores to provide price comparison services. For example, they crawl product information from various online shopping malls to help users find the cheapest prices.

※ In Korea, you can see information from various shopping sites, not just 'Naver', when you search on 'Naver Shopping'. "Danawa" site is also similar.

Social Media Crawling : Information publicly available on social media can be crawled and used for trend analysis, marketing strategy development, etc. For example, there are tools that collect and analyze information on specific hashtags or topics from Twitter.

Crawling is a key technology that enables various web services, including search engines. However, when crawling, you need to comply with the website's Robots Exclusion Standard (Robots.txt) and privacy regulations.