A set of OML variables in which each variable is defined with a name and value. An expression can be evaluated in a workspace if all the variables used in the expression are in the workspace. Each diagram has its own workspace obtained from the evaluation of the model initialization script, the contexts of any parent diagrams, and the diagram's own context.

The base workspace refers to the workspace of an OML session open in the OML command window. The blocks ToBase and FromBase, in particular, communicate with this workspace.