Workflow Binds
A binding allows you to specify the source from which the actual value will be obtained. When the value for the source changes, the bound property value will automatically update, as well.
Forms and Binds
When you perform binds on form control properties, the above information is also true, with the addition of the following information.
For some properties, you can also create a two-way binding, whereby if the bound property value changes, the source also changes. This type of scenario is property dependent; that is, it does not apply to all properties on all form controls.
Bindings that involve input parameters or output parameters are explicitly created as one-way bindings. For example, if you bind from an output parameter's Value property to the Text property of a text box, then if the text in the text box changes, the output parameter updates. However, if the output parameter's Value property changes, the text box's Text property does not update.