Cybersex, also called computer sex, Internet sex, netsex and, colloquially, cyber or cybering, is a virtual sex encounter in which two or more people connected remotely via computer network send each other sexually explicit messages describing a sexual experience. In one form, this fantasy sex is accomplished by the participants describing their actions and responding to their chat partners in a mostly written form designed to stimulate their own sexual feelings and fantasies. Cybersex often includes real life masturbation. Environments in which cybersex takes place are not necessarily exclusively devoted to that subject, and participants in any Internet chat may suddenly receive a message of invitation. The quality of a cybersex encounter typically depends upon the participants' abilities to evoke a vivid, visceral mental picture in the minds of their partners. Imagination and suspension of disbelief are also critically important. Cybersex can occur either within the context of existing or intimate relationships, e.g. among lovers who are geographically separated, or among individuals who have no prior knowledge of one another and meet in virtual spaces or cyberspaces and may even remain anonymous to one another. In some contexts cybersex is enhanced by the use of a webcam to transmit real-time video of the partners.