TelePresence Management Suite is used for conference scheduling and management of endpoints.
TelePresence Conductor is used to manage conference bridges, such as MCU and TelePresence Server.
TelePresence Server is used to host multipoint video conferences.
To read more about what each product can do, take a look at their data sheets for more information: TMS Data Sheet, Conductor Data Sheet, and TelePresence Server Data Sheet.
Note, Conductor and TelePresence Server are soon to be end-of-sale on Feb 2018, the recommended conference bridge going forward is Cisco Meeting Server, CMS Data Sheet.
Also, take a look at the Cisco Collaboration Preferred Architectures, it will give you a good idea of what each product does and how it fits together to provide a collaboration solution.
