When you are recording you can select two options. One is replace, this means that the record replaces the previous recorded track or creates a new one. The second one is overdub, this one simply add a new recording to the previous track.
This button means cycle and loops a
The l and R are locators you can set them by using right or left mouse button on to of the screen. Locators are use for many things for example. Set
to use cycle, recording form and stop and to use out punch in.
Place of the locators
Punch in and out, use this to activate recording from playback mode. Use locators to activate.