Reading a Waveform
A waveform is a graphic representation of a sound wave. It gives you an idea of the volume of sound at various track segments. For example, the picture below shows a waveform of a song that starts with a soft voice part followed by a short pause and continued with an intense loud chorus. 
The waveform can help you detect the segment of interest without having to listen to the entire track. This may be useful, for example, when you want to extract a chorus from a song.
Keyboard Control
If you need high accuracy when detecting the interval to cut, it is helpful to use right and left arrow keys on the keyboard. When pressed, these keys shift the selected slider by a fraction of s second. The spacebar can be used to start and stop the playback of a track.
Fade-in and Fade-out
It sometimes sounds best if a track you cut would fade smoothly on start and gradually grow louder. For that matter we introduced the functions of "Fade-in" and "Fade-out".
When the "Fade-in" function is enabled, the interval starts with silence and gradually grows louder.
When the "Fade-in" function is disabled, the interval starts at a standard volume.