A virtual learning environment (VLE) is an education system based on the Web that models conventional real-world education by integrating a set of equivalent virtual concepts for tests, homework, classes, classrooms, and the like, and perhaps even museums and other external academic resources. It normally uses Web 2.0 tools for 2-way interaction, and includes a content management system. Virtual learning environments are the basic component of contemporary distance learning, but can also be integrated with a physical learning environment; this is sometimes referred to as Blended Learning. A virtual learning environment includes web-based access to class content, grades, assessments, and other class tools. It is also a social space where students and teacher can interact through threaded discussions or chat. A virtual learning environment can also include students and teacher _meeting_ online through a synchronous web-based application.