Profiles represent the highest level of control. A profile can contain lists, action lists and actions themselves. Because all other filters can be added to a profile, only one can be active at a time.
A profile has to be populated for any action to take effect. If no entries exist, the profile will act accordingly and take no action.
We recommend you create profiles like "Block everyone", "Important calls only", "Weekend" or "Weekday". Of course these are only suggestions, we are quite certain intelligent guys like you will come up with more appropriate generalisations.
The schedueling system uses profiles exclusively, so if you need to set up a weekly schedule, you should create multiple profiles, only one of which will be active at a time.