Browser caching locally stores frequently accessed resources. This improves website loading speed by reducing the need to fetch resources from the server.

Yes, it does. An overloaded or slow server can delay content delivery.

This could be because of factors such as inefficient code, unoptimised images, server performance issues, or excessive HTTP requests.

You can do so by optimising images, improving server configuration, optimising code, leveraging caching, and minifying/combining files.