In Structurizr terminology, a "workspace" is a wrapper for a software architecture model (elements and relationships) and views.
workspace "Name" "Description" {
model {
}
views {
}
}
A workspace can be given a name and description, although these are only used by the Structurizr cloud service and on-premises installation - you don't need to specify a name/description if you're exporting views to one of the export formats (PlantUML, Mermaid, etc).