Swar Performer implements various objects. It is important to understand them and how they interact.
Tracks come in 3 types:
Swar Performer lets you create all 3 types and configure them specifically through gain, panning and possibly effects.
Devices are what produces the MIDI events that are directed to tracks. Swar Performer lets you create one or more devices, which are virtual by default, but can be connected to one of your physical ones, so you can play from your own hardware directly.
Mappings are what links specific key ranges on the devices to specific tracks. They are very flexible, so that you can have separate key ranges in a single device targeting different tracks, or mappings on different devices targeting the same track.
Mappings are specific to scenes, which means that changing scenes changes the way your keyboard(s) interact with tracks. You can change scenes by clicking on them, or by recording a specific key/button from your keyboard, and then pressing that. This gives you full freedom to change the instruments played on the fly during your performances.
Sessions are the documents that are created/loaded and saved in Swar Performer. A session contains a full configuration made of all the objects above. Typically you may need to use different sessions in a performance if your setup needs a more drastic change that can't be achieved by scenes only.