When we use the term container...
In the facilitation of transformative experiences - "the container" can refer to the agreements that are made, the dedication of the time spent, an open statement of the purpose of the time, the roles that are identified and utilized, and how well these aspects are kept in place. Imagine the experience like a conduit - the container focuses energy in a particular direction and supports it in sustaining momentum in that direction.

Examples of questions that might go into creating a container:
What is our purpose for gathering here today?
What is our time here dedicated to?
In what ways shall we relate with each other that our time might serve this purpose and dedication most fully for each person here?