Fishbowl meetings have an inner circle of chairs and an outer one. Those on the inside (the fishbowl) discuss a topic, and those outside observe. Individuals can enter and leave the fishbowl to join or exit the conversation as appropriate.
Summary by The World of Work Project
Fishbowl Meetings: An Opportunity to Observe
A fishbowl meeting is a specific type of activity designed to allow some individuals to take part in a conversation, and others to observe the conversation.

The meetings work by having two circles of chairs, an inner circle and an outer circle. This can be replicated virtually using platforms like Zoom, and there are some other collaboration platforms that are specifically designed with them as a feature.
The inner circle is known as the fishbowl and usually contains perhaps 4-8 chair. The outer circle can be significantly larger so that many people can observe the conversation.
The meeting works as follows. The individuals who are sitting in the inner circle have a conversation and discussion among themselves on a specific agreed topic, perhaps based on some primer questions, and are observed by those in the outer circle. There’s a set time for the conversation, and a broad topic for discussion, but the conversation can grow and flow as the participants desire.
In conventional fishbowl meetings individuals can choose to enter or leave the fishbowl (one at a time). Those leaving tend to be replaced by someone from the outer circle. In this way the conversation can carry on with new perspectives as it evolves. This also gives individuals the opportunity to step away when they want time to reflect, or when they think they have contributed enough for that moment in time.

Learning More
You might also be interested in facilitation and team building, or world cafes, lightning talks, birds of a feather meetings or communities of interest.
You can learn more about team building activities in our podcast on them:
The World of Work Project View
Conventional fishbowls are a helpful tool in organizations for supporting sustained and engaging conversations. They provide an opportunity for a large group to take part in quite an intimate conversation and are a great alternative to panel discussions or presentations.
The opportunity they provide for people to “tag in” and “tag out” of the conversation means they lend themselves well to fairly informal and non-hierarchical discussions. This also means, though, that some people will be scared of them for exactly these reasons.