Web crawlers are essential components of the internet infrastructure, primarily used by search engines like Google and Bing to collect and index data, which allows them to provide relevant search results to users. These software robots operate by scanning websites, downloading data, and adhering to protocols such as the robots.txt file, which guides their access and indexing behavior. Besides aiding in search engine optimization (SEO) by ensuring content is discoverable, web crawlers also face several challenges, including robots.txt restrictions, IP bans, geolocation limits, and CAPTCHA obstacles. While they cast a wide net in data gathering, web scrapers are more targeted, often used by companies for competitive analysis. Despite these challenges, web crawlers remain indispensable for maintaining the functionality and efficiency of online search engines.