As shown in the image above the "Print Check Simple Process" has one parameter named "Check Number".
That parameter is an "In" "Parameter Type" which "Input Type" is "Text".
Above configuration means that the check number needs to be enter as a text by the user.
An "In" parameter type can also be a checkbox, therefore instead of entering a text the user needs to select a checkbox or not.
It is also possible to define whether the default value of the checkbox is going to be "Yes" or "No".
Besides the parameter types can also be a "Constant", therefore the "Default Text Value" of the constant can be specified.
The value register for any of the above defined parameter's types is saved in the Parameters tab of the corresponding payment run.