According to the American Heritage Dictionary,“virtual” is defined as existing in essence or effect though not in actual fact or form. Thus, virtual reality is an entity which contains the essence of reality and is effectively real. It can provide a basis for technology which enables humans to experience events and act in a computer-synthesized environment just as if they were in a real environment. Although telexistence (tel–existence) is essentially the same concept as virtual reality, it takes a different point of view. It represents a new concept, which frees humans from the restrictions of time and space and allows them to be effectively present in places other than their current location as well as to interact with those remote environments, which may be real, computer-synthesized, or a combination of both. Thus, virtual reality and telexistence are essentially the same concept expressed in a different manner. Usually, virtual reality is used for computer-synthesizedworlds, while telexistence is used for the real world. However, both concepts can be regarded as tools for communication, control, and creation (the 3Cs) or entertainment, experience/education, and elucidation (the 3Es).
(Cited from Susumu Tachi,"Telexistence," World Scientific, 2010)