Organizations are the highest hierarchical level, they contain all the Spaces and Collections. You can create multiple organizations to further separate your content. For example, create a Personal Organization as well as a Work organization and switch between them at any time. 

Creating an Organization

1. Click the '+' underneath the circle icons, on the left-most sidebar.

2. Name your new organization

Note: the first two letters of the Organization name will appear within the circle. If it is two words then the first letter of each word will become the initials.

At this point, you can also add new members to the Organization by clicking "Add members".

Type in the email of your new members and click 'Invite' to automatically invite them to join the Organization.

3. Click Create

3. Your new Organization will appear on the left sidebar.