When you sign up as a new user, you get presented with some choices:
Every new Kerika account gets a free 30 day trial, during which you can create as many boards as you liked, and share them with as many people as you like.
After your 30-day trial is over, you will still own your account, and any boards that you had previously created, and you will continue to be able to create new boards in your account. However, if you want to continue to have others work as Team Members or Board Admins, content and canvases – then you will need to pay for them.
Each account is associated with a specific email address:
The Account Owner has ultimate authority over all boards owned by that account:
Here's an example: this Account has three boards, with a mix of Team Members and Visitors. (The Team Members are highlighted here in red circles, and the Visitors in blue circles.)
Everyone who is a part of the Account Team can create new boards: these are automatically owned by that account, regardless of who created them.
Each board can be kept private or shared with the rest of the Account Team, and each board can have its own set of Board Admins, Team Members, and Visitors.