The following section defines what a Lock is in ActivityInfo.
In ActivityInfo, a Lock is a restriction which prevents Users from adding or editing data for a particular time period.
Depending on your needs, a Lock can be set on any Form or Subform that has a Date/Month/Week field added as a Key field.
Locks allow you to stop Users from adding data for the wrong time period for example. They also allow you to preserve versions of your data after they have been validated by your information management processes.