Crawling

Crawling (or spidering) is the automated process of systematically browsing the web to index and collect information from websites. It is commonly used by search engines to gather data for indexing, but it can also be employed for various other purposes, including security assessments, data mining, and competitive analysis. Crawlers, also known as spiders or bots, follow links on web pages to discover new content and extract relevant information.

How Crawlers Work

1. Starting Point: Crawlers begin with a list of seed URLs to visit.
2. Fetching: The crawler sends HTTP requests to these URLs to retrieve the web pages
3. Parsing: The retrieved pages are parsed to extract links and relevant data.
4. Link Following: The extracted links are added to the list of URLs to visit
5. Repetition: Steps 2-4 are repeated for the new URLs until a specified depth or limit is reached.

Breadth-First vs. Depth-First Crawling

• Breadth-First crawling explores all links at the current depth before moving to the next level, while Depth-First crawling follows a single path down to its end before backtracking. Each method has its advantages and disadvantages depending on the use case.
• Depth-First crawling follows a single path down to its end before backtracking.

Each method has its advantages and disadvantages depending on the use case.