The Church allows four different kinds of penance services.
The first and most common is private, individual Confession. This is the most commonly used form of penance service, and most of us are familiar with it.
The second type of penance service is usually called General Absolution. This is very rare, and to be used only in extraordinary circumstances when the bishop authorizes it or practical needs require its use. General Absolution is given only when the number of penitents is large, and the danger of death is great, or a large number of penitents cannot wait for private individual confession because of unusual circumstances such as natural disasters, wartime conditions, and other calamities. When general absolution is given, the penitents are given absolution as a group without confessing their sins to a priest, with the understanding that they will go to individual confession at the earliest opportunity.
A third type of penance service is a Non-sacramental Penance Service. This is simply a prayer service in which we acknowledge that we are sinners and pray for forgiveness and renewal. Such a penance service does not involve sacramental confession, and therefore there is no absolution or the remission of sins.
The fourth type of penance service is usually called a Communal Penance Service. Many parishes, including St. Thérèse of Carmel, hold communal penance services during Advent and Lent. This is a form of sacramental confession and mixes public prayer and individual confession of sins to a priest, followed by absolution.