A monstrance is the vessel used in the Roman Catholic, Old Catholic, and Anglican churches to display the consecrated Eucharist

Eucharist

The Eucharist , also called Holy Communion, the Sacrament of the Altar, the Blessed Sacrament, the Lord's Supper, and other names, is a Christian sacrament or ordinance...

ic host

Sacramental bread

Sacramental bread, sometimes called the lamb, altar bread, host or simply Communion bread, is the bread which is used in the Christian ritual of the Eucharist.-Eastern Catholic and Orthodox:...

, during Eucharistic adoration

Eucharistic adoration

Eucharistic adoration is a practice in the Roman Catholic Church, and in a few Anglican and Lutheran churches, in which the Blessed Sacrament is exposed to and adored by the faithful....

 or Benediction of the Blessed Sacrament

Benediction of the Blessed Sacrament

Benediction of the Blessed Sacrament is a devotional ceremony celebrated within the Latin Rite of the Roman Catholic Church, as well as in some Anglican and Lutheran Churches, Liberal Catholic churches, Western Rite Orthodox churches, and Latinised Eastern Catholic Churches.Benediction of the...

. Created in the medieval period for the public display of relic

Relic

In religion, a relic is a part of the body of a saint or a venerated person, or else another type of ancient religious object, carefully preserved for purposes of veneration or as a tangible memorial...

s, the monstrance today is usually restricted for vessels used for hosts. The word monstrance comes from the Latin word monstrare, meaning "to show", and is cognate with the English word demonstrate, meaning "to show clearly".