In architecture, a niche is a recess or cavity constructed in the thickness of a wall for the reception of decorative objects such as statues, busts, urns, and vases. In Classical architecture example
Niche with a sculpture by Antoine Coysevox, in the Les Invalides, Paris
Mihrab from the Mosque of Cordoba (niche shows the direction of prayer)
Porta Maggiore niches appear between arches.
Niches containing statues on exterior of Church of Orsanmichele, Florence, c. 1380–1404
In architecture, an apse is a semicircular recess covered with a hemispherical vault or semi-dome, also known as an exedra. In Byzantine, Romanesque, and Gothic Christian church architecture, the term
Niche (architecture)
…of a wall for the reception of decorative objects such as statues, busts, urns, and vases. In Classical architecture examples are an exedra or an apse that has been reduced in size, retaining the half-dome heading usual for an apse. In the first century B.C, there was no exact mention of niches, but…
Typical early Christian Byzantine apse with a hemispherical semi-dome in the Basilica of Sant'Apollinare, Classe, Italy
Triple apse of Basilica di Santa Giulia, northern Italy
East end of the abbey church of Saint-Ouen, showing the chevet, Rouen, Seine-Maritime, France
A chevet apse vault, Toulouse, France