Child Routes & Lazy Loading in Angular

Child routes are more than just a way to group URLs. They allow you to build persistent layouts. When navigating between children of the same parent, the parent component is NOT destroyed. This means you can have a persistent sidebar, header, or state in the parent while only the content inside the child's <router-outlet> changes. This is the key to building complex, stateful dashboards.

Lazy Loading is a 'must-have' for large apps. By splitting your application into feature modules and only loading them when needed, you drastically reduce the 'Time to Interactive'. Angular handles the complexity of fetching the JavaScript chunks behind the scenes, providing a smooth experience for the user while keeping the initial download size minimal.