A public board is a board with a unique URL that is very hard to guess, and anyone that has the URL can access the board. The URL is not publicly available, and we don't index it on search engines as well.
Public boards are great for events with a large number of people, especially because public boards allow users to use them without the necessity of creating an account on EasyRetro.
Note: Please be careful with who you share the URL with. If you are dealing with sensitive data, you should use private team boards, or be sure to delete the public board after you finish your meeting.
A team board is more secure because only people that you invite to your team will have access to it. You can add and remove team members at any time.
Team boards are better for a fixed group of people that does recurring meetings together. Especially if the people in the group usually don't change very often.
The main difference is that public boards are attached to personal accounts. Only the board creator can see the public board on their Dashboard page, and also anyone that has the URL can have access to a public board.
Team boards are private. Only people that you invited to the team will have access to it. Also, everyone on your team will be able to see the team boards on their Dashboard page.