The dalmatic is a long, wide-sleeved tunic, which serves as a liturgical vestment in the Catholic, Lutheran, Anglican, United Methodist, and some other churches. When used, it is the proper vestment of a deacon at Mass, Holy Communion or other services such as baptism or marriage held in the context of a Eucharistic service. Although infrequent, it may also be worn by bishops above the alb and below the chasuble, and is then referred to as pontifical dalmatic.
A Roman Catholic deacon exhibiting a dalmatic and a biretta during a service in the Traditional Latin Rite
Ornately embroidered dalmatic (shown from the back with a collarin)
Roman Catholic deacon wearing a dalmatic
Dalmatic Roman usage (with its closed sleeves)
A tunic is a garment for the body, usually simple in style, reaching from the shoulders to a length somewhere between the hips and the knees. The name derives from the Latin tunica, the basic garment worn by both men and women in Ancient Rome, which in turn was based on earlier Greek garments that covered wearers' waists.
Coptic-Byzantine wool tunic, small enough for a child (6th century AD) (Walters Art Museum)
Germanic tunic of the 4th century AD found in the Thorsberg moor
20th-century Yemenite Jews dressed in tunics