It is a list of time offsets, or locations defined within an audio file or session. You can enter here information on the position of either a point, specifying the cursor position, or a range, specifying a selection. Markers is a floating window, meaning you can click in the waveform on the main Expstudio Audio Editor window (to define your markers) leaving the Markers window open. You can find a marker in the waveform by double-clicking on the marker in the list.