Runserver is a bundled webserver similar to whats provided with Rails and Django projects. Developers may now
cd into any Drupal codebase, run
drush runserver, and then start browsing the site. This skips all webserver and vhost configuration.
qd is short for Quick Drupal. It clones Drupal, starts a webserver for the site, installs Drupal, and logs you in as an admin in your browser.