Alb

The alb (from the Latin Albus, meaning white), one of the liturgical vestments of the Roman Catholic, Anglican, Lutheran, and Methodist churches, is an ample white garment coming down to the ankles and is usually girdled with a cincture (a type of belt, sometimes of rope similar to the type used with monk garments). It is simply the long, white linen tunic used by the Romans.

As a simple derivative of ordinary first-century clothing, the alb was adopted very early by Christians, and especially by the clergy for the Eucharistic liturgy. In early Medieval Europe it was also normally worn by secular clergy in non-liturgical contexts.

Nowadays, the alb is the common vestment for all ministers at Mass, both clerics and laypersons, and is worn over the cassock and under any other special garments, such as the stole, dalmatic or chasuble. If the alb does not completely cover the collar, an amice is often worn underneath the alb. The shortening of the alb for use outside a church has given rise to the surplice, and its cousin the rochet, worn by canons and bishops. Post-Tridentine albs often were made with lace. Since then, this detail has fallen out of style, except in parts of the Anglo-Catholic movement and some very traditional Arab Catholic parishes.

...
Wikipedia