HtmlUnit is a headless browser used for modeling and interacting with HTML pages programmatically, enabling tasks like form completion, submission, and navigation between pages. It is particularly useful for web scraping and automated testing to ensure web pages perform as expected. The process involves creating a Gradle project in IntelliJ IDEA, which supports Gradle integration, to manage dependencies and build automation. HtmlUnit allows for both static and dynamic web page scraping, using methods such as getByXpath() and getElementById() to identify and extract data from HTML elements. For dynamic pages, it can fill forms, click buttons, and navigate pages, demonstrated through a case study on the Hacker News website. While HtmlUnit offers robust scraping capabilities, alternatives like Bright Data's Serverless Functions provide unblocking proxy infrastructure and pre-built scraping functions to address challenges like IP blocking and rate limiting, offering a more efficient solution for certain use cases.