Cascading Style Sheets are the files responsible for the presentation of a website. All rules that affect the visual formatting are stored in these files. This lets the developer keep style information in a separate place from the content.

This separation strategy has a few benefits:

  • Stylesheets may be cached, improving page load times
  • May prevent the person in charge of updates from accidentally disturbing the design
  • Stylesheets may be made interchangeable, allowing the webmaster to change the appearance of a website while not affecting content.