A Static Site Generator (SSG) is a tool that creates a website by converting plain text files into static HTML pages. Unlike traditional web development, which often relies on databases and server-side processing, SSGs pre-build all the pages at once. This results in faster load times and improved security since there are fewer moving parts. Commonly used SSGs include Jekyll, Hugo, and Gatsby. These tools allow developers to write content in formats like Markdown and then generate a complete website with a single command. Static sites are ideal for blogs, portfolios, and documentation, where content doesn't change frequently.