Today - there is only 1 workspace per account/plan at this time.
Each Workspace comes with UNLIMITED PROJECTS
.. to better organize your work.
We have agencies that buy different plans for various departments/teams and each one gets its own workspace. A user/admin can have many workspaces.
A project is a subset of the workspaces, to allow for greater refined organization of .. projects. Since one team can have many different projects.
So you can have something like this:
Workspace = CoolAgency-UX
---Projects = COKE
------Sitemaps = Coke.com(Audit), Coke.com(Optimized)
------Flow = Coke's User Journey
Every member in the workspace can crawl with no restrictions.