（中文在後）In vinyl records, "analog" literally means the shapes of the grooves are analogues to the shapes of the sound waves recorded. In the figures below, the blue lines highlight a left-channel only sine wave groove. The red lines are for a right channel groove. During playback of these grooves, the stylus moves in the corresponding blue or red arrows as in the 3rd figure. For mono grooves in the 4th figure, the stylus moves horizontally as marked by the purple arrow in the 5th figure.
所謂「類比」analog，在黑膠的場合就是溝槽的形狀，等同播放出的聲波形狀。播放時如果用Visual Analyser等軟體/儀器，就看得到波型。
以下藍色標示為顯微鏡下左聲道正弦波黑膠溝槽，與播放該溝槽時針尖運動方向。紅色則是右聲道。無標示的圖是MONO溝槽，紫色箭頭是針尖播放MONO溝槽時的運動。
