The _next<\/strong> directory is a reserved path used by the Next.js<\/a> framework to serve internal assets, build manifests, and pre-rendered data. When a React<\/a> application is built using the This directory plays a critical role in Client-Side Rendering<\/a> and Hydration<\/a>. It contains various sub-directories, most notably Security and infrastructure configurations, such as those found on Vercel<\/a> or AWS<\/a>, often need to account for this path to ensure that Caching<\/a> headers are correctly applied to immutable assets. According to the Next.js Documentation<\/a>, the default distribution directory can be renamed, but the public-facing next build<\/code> command, the resulting production files are typically stored in a hidden .next<\/code> folder. However, when these assets are served to the client, they are exposed via the \/_next\/<\/code> URL prefix.<\/p>\/_next\/static\/<\/code>, which holds JavaScript<\/a> chunks, CSS<\/a> files, and images optimized by the Next.js Image Component<\/a>. For applications utilizing Static Site Generation<\/a> or Server-Side Rendering<\/a>, the \/_next\/data\/<\/code> path is used to fetch JSON<\/a> files containing the props required for page transitions without a full browser reload.<\/p>\/_next\/<\/code> prefix remains a standard for the framework's internal routing mechanisms managed by Webpack<\/a> or Turbopack<\/a>.<\/p>