The word rood is derived from the Saxon word "ROOD" or rode, meaning "cross".

The rood screen is so called because it was surmounted by the Rood itself, a large figure of the crucified Christ. Commonly, to either side of the Rood, there stood supporting statues of Saints, normally Mary and Saint John, in an arrangement comparable to the Deesis always found in the centre of an Orthodox iconostasis (which uses John the Baptist instead of the Apostle, and a Pantokrator instead of a Crucifixion).

Latterly in England and Wales the Rood tended to rise above a narrow loft (called the "rood loft"), which could occasionally be substantial enough to be used as a singing gallery (and might even contain an altar); but whose main purpose was to hold candles to light the rood itself. The panels and uprights of the screen did not support the loft, which instead rested on a substantial transverse beam called the "rood beam" or "candle beam". Access was via a narrow rood stair set into the piers supporting the chancel arch. In parish churches, the space between the rood beam and the chancel arch was commonly filled by a boarded or lath and plaster tympanum, set immediately behind the rood figures and painted with a representation of the Last Judgement. The roof panels of the first bay of the nave were commonly richly decorated to form a celure or canopy of honour; or otherwise there might be a separate celure canopy attached to the front of the chancel arch.

The carving or construction of the rood screen often included lattice work, which makes it possible to see through the screen partially from the nave into the chancel. The term "chancel" itself derives from the Latin word cancelli meaning "lattice"; a term which had long been applied to the low metalwork or stone screens that delineate the choir enclosure in early medieval Italian cathedrals and major churches. The passage through the rood screen was fitted with doors, which were kept locked except during services.

The terms; pulpitum, Lettner, jubé and doksaal all suggest a screen platform used for readings from scripture, and there is plentiful documentary evidence for this practice in major churches in Europe in the 16th century. From this it was concluded by Victorian liturgists that the specification ad pulpitum for the location for Gospel lections in the rubrics of the Use of Sarum referred both to the cathedral pulpitum screen and the parish rood loft. However, rood stairs in English parish churches are rarely, if ever, found to have been built wide enough to accommodate the Gospel procession required in the Sarum Use. The specific functions of the late medieval parish rood loft, over and above supporting the rood and its lights, remain an issue of conjecture and debate. In this respect it may be significant that, although there are terms for a rood screen in the vernacular languages of Europe, there is no counterpart specific term in liturgical Latin. Nor does the 13th century liturgical commentator Durandus refer directly to rood screens or rood lofts. This is consistent with the ritual uses of rood lofts being substantially a late medieval development.