Software developers need to know which platform their software will be running on. A platform can be an Intel processor running Windows, a Macintosh running System 8, or any combination of hardware and software that works together. Platforms are important for web designers to understand, because they need to make sure their pages will work on more than one platform. Different browsers display web pages differently on various platforms. Since the internet itself is a cross-platform system, designers need to test web pages on different combinations of machines and browsers to ensure the widest possible audience will be able to view their sites.