Standards-compliance is the compliance of a website or web browser with the web standards of the World Wide Web Consortium (W3C). To ensure interoperability a standards-compliant web site does not use proprietary software methods or features of a browser. Current use of the term “standards-compliance” generally refers to the adherence to coding practices in relation to the use of HTML or XHTML, with Cascading Style Sheets (CSS) to define the layout, colors, and fonts of a web page.