What's the Difference Between Undo and Go Back?

At first glance, the and the might appear to be performing the same function. In practice, the two functions are closely related, but there are important distinctions between the two:

• Use Undo to correct any mistakes you make while working on the current design iteration. Use Go Back to revert to a previous design iteration. The Go Back function is normally used as part of the optimization process, rather than to correct drawing or editing errors.
• Undo is only available for the three most recent changes to your , but you can Go Back to any previous design iteration created during the current .
• Because Undo only applies to the current design iteration, the Undo function is disabled whenever you Go Back to a previous iteration. Undo is enabled again as soon as you make any new changes to the structural model.