Yes. In your configuration.yaml, add group: !include groups.yaml (you’ll need to create groups.yaml first). Then, restart HA. After that, you’ll be able to reload groups without a restart. However, I think that if you have group: defined in your configuration.yaml, you don’t need to restart to load changes made to groups.
Light groups only allow for lights and offer features like dimming and color control whereas a generic group allows for anything to be grouped together. So, if you have 3 switches in a room and you want to control them all at the same time, or if you want to turn off an entire room using one group, you could add all the entities in that room to a group and control all of them at the same time.
room_switches:
name: Room Switches
entities:
- switch.room_switch1
- switch.room_switch2
- switch.room_switch3
Office:
name: Office
entities:
- switch.office_switch1
- light.office_light1
- light.office_light1