The jinja is the Shinto shrine, the dwelling of a kami and the ordinary place of its worship, and it is the general term of which the grander shrine titles are particular ranks.
A dwelling, not an assembly hall
A jinja enshrines one or more kami, whose presence is focused in the hidden object, the shintai, kept in the inmost sanctuary; the ordinary worshipper approaches only the outer hall of worship, passes beneath the torii gate that marks the boundary of sacred ground, purifies the hands and mouth at the water basin, and makes an offering with a bow and a clap. The shrine is not primarily a place of congregation and preaching, since Shinto has little doctrine to teach, but a place where the kami is present and can be approached with purity and offering.
From the local to the national
Japan holds tens of thousands of jinja, ranging from great institutions with a professional priesthood to small roadside shrines with none, and most are affiliated to the Association of Shinto Shrines, which certifies their priests and coordinates their observances. The word jinja is the base term, while jingu and taisha are higher designations reserved for shrines of particular rank or antiquity. The density of shrines across the landscape, many marking a mountain, a wood or a rock held to be the seat of a kami, is one of the most visible features of the Japanese religious environment.