What is a retreat?

As we near the time for our annual parish retreat I thought that I’d respond to some questions that I’ve been asked about retreats and their purpose.
What is a retreat, what purpose does it serve and why should I consider one?
One: What exactly is a retreat?
A retreat is a period of time that a person sets aside to examine and improve one’s relationship with God. The length of a retreat will vary. There is a month – long retreat based on the Spiritual Exercises of St. Ignatius; a retreat can be a week in duration; our parish retreat is a weekend; even a day of reflection can be viewed as a retreat.
A retreat can be done individually between a person and a spiritual director. A retreat can also occur in a group setting with time available for individual reflection and contemplation.
Retreats revolve around a theme or topic. For example, the parish retreat this year will focus on Pope Francis.