Answer
Brief description
You have 10-200 characters to sum up what people attending your event can expect. It will be shown to users in event search results, so it’s worth taking the time to formulate this description text in a concise and appealing way.
Long description
This is intended to provide those coming to your event with more details. You’ll want to include all the important organisational information people need to know, and possibly items you have planned, speakers and hosts, etc.