To Countryboy879:
A simple answer to your original question is: they are all Narrowband Frequency Modulation (NFM) for both the input and receive mode.
A note for you to consider on why you got the responses above: The above posters are just concerned that if you are programming a radio to transmit and receive, be sure that you are authorized to do so from each agency/department, and have that in writing specifically. They are just looking out for your own protection, since one (or more) are involved with the Department of Homeland Security and related agencies. There have been a number of incidents where individuals had radios programmed with various freq's (not just police) and were found to NOT be authorized to transmit on the particular frequency. A scanner is different, since it's only receive mode, and that varies by town and State law. Some individuals have two-way radios programmed as receive mode only, with no transmit possible. That's ok too without having to obtain permission from that agency/department.