Focused crawls are collections of frequently-updated webcrawl data from narrow (as opposed to broad or wide) web crawls, often focused on a single domain or subdomain.
The WebProfilerBundle provides detailed technical information about each request execution and displays it in both the web debug toolbar and the profiler.
WebServerBundle provides commands for running applications using the PHP built-in web server. It simplifies your local development setup because you don't have to configure a proper web server such as Apache or Nginx to run your application.