Maintain Consistency

Moreover, a single style sheet can be reused by many documents. The work of defining a standard style need only be done once; afterwards the style sheet can be reused many times. Plus, having many documents share the same style sheet means that they style of all the documents can be updated at the same time by modifying the shared style sheet. This reduces the cost of maintaining large collections of documents over the long run. It's easier to achieve a standard look and feel for documents across an organization, and it's easier to change that look and feel when you need to.