Customers
Customers are users of the frontend store. They can be assigned to a customer group and organization.
Only each particular customer can see its own data on the frontend store and only while being logged in.
However, back office users can impersonate customers on the frontend store. Also, customers themselves can be allowed to impersonate other customers.
Create an organization

Fill in the required fields and set the state to "Active" to make the organization active.
Click on "Save organization" to complete the process.
Create a customer

Set the channel, email, state, password and group. Fill in the required attributes, like first name and last name.
Optionally, assign the customer to an organization.
Customer state must be "Active" to be able to log in.
Click on "Save customer" to complete the process.