Your account is your personal login to Screenly. You use it to sign in, and to join the workspaces you have access to. That is its whole job.
What it is not is a home for your work. Your screens, content, playlists, and schedules do not live in your account. They live in a workspace.
The difference matters as soon as you work with other people. Several people can each have their own account and all work inside the same workspace. Your account is only ever about you: who you are and how you sign in. The workspace is where the work happens.