In Christianity, the term was originally applied to a Christian who lives the eremitic life out of a religious conviction, namely the Desert Theology of the Old Testament (i.e., the 40 years wandering in the desert that was meant to bring about a change of heart).
In the Christian tradition the eremitic life is an early form of monastic living that preceded the monastic life in the cenobium. The Rule of St Benedict (ch. 1) lists hermits among four kinds of monks. In the Roman Catholic Church, in addition to hermits who are members of religious institutes, the Canon law (canon 603) recognizes also diocesan hermits under the direction of their bishop as members of the consecrated life. The same is true in many parts of the Anglican Communion, including the Episcopal Church in the US, although in the canon law of the Episcopal Church they are referred to as "solitaries" rather than "hermits".
Often, both in religious and secular literature, the term "hermit" is also used loosely for any Christian living a secluded prayer-focused life, and sometimes interchangeably with anchorite/anchoress, recluse and "solitary". Other religions, for example, Buddhism, Hinduism, Islam (Sufism), and Taoism, also have hermits in the sense of individuals living an ascetic form of life.
In modern colloquial usage, "hermit" denotes anyone living apart from the rest of society, or simply participating in fewer social events, for any reason.