Only the account Administrator can create new teams or move a User from one team to another. After logging in, click on the 'Account settings' link, followed by the 'Team Management' button. The Users attached to your account will be displayed. Each User belongs to a Team, which is displayed in a drop down box next to the password field.
The Administrator can organize Users into teams according to their needs for example, all the Users in the Marketing Department can be grouped together into one team, all users in Human Resources into another team, and so on.
When a User logs in, he/she will only be able to view his own surveys and the surveys created by his team.