Whether done on one's own time or at a scheduled service, adoration of the eucharistic presence of Christ fosters our devotion for participation in the Mass. Jesus instituted the Eucharist for our eating and drinking. Sharing communion at Mass brings us nourishment, healing and sustenance.
Catholics reserve leftover communion breads in a tabernacle.
The primary purpose for this custom is to have the Body of Christ ready for the dying at any time. Mass. Because it houses the sacramental Body of Christ, it serves as a place for adoration. Adoration may be private or public. When adoring the Blessed Sacrament in private, Catholics usually go to any church, where the communion hosts are kept inside the tabernacle. They say whatever prayers they wish.