This document discusses URLs and URL design. Some key points covered include: - URLs should be meaningful and describe the content or functionality behind them. File structure and naming conventions in URLs can help with this. - URL rewriting techniques like Pretty URLs can make URLs cleaner and more readable for users and search engines. - Namespaces, routing conventions, and RESTful design principles can help organize URLs and map URLs to application functionality. - Vanity URLs, long URLs, and duplicate or dangling URLs should generally be avoided for usability and maintenance reasons.