In computer networking, the term quality of services (QoS) describes resource management rather than the quality of a service. Quality of services implements control mechanism to provide different priority to different users, applications, and data connections. It is used to guarantee a certain level of performance to data resources. The term quality of service is often used in the field of wide area network protocols (e.g. ATM) and telephony (e.g. VoIP) but rarely in conjunction with web applications. mod_qos is a quality of service module for the Apache web server implementing control mechanisms that can provide different priority to different HTTP requests.