About the Convergence Plot and Progress Window
The gradient-based solvers create a Convergence Plot that displays the number used for the Convergence criteria as a function of the iteration numbers; see About Optimality Tolerances.
An extra line is also added to the Progress window, which shows the number used for the Convergence criteria. This line also shows the objective, and next to it there is a Stop button that allows premature termination of the optimization algorithm. Finally, the forward sensitivity method is associated with an extra line in the Progress window where the control number is displayed; see Forward Sensitivity.