 
 <prompt> Wetin aspect of CD dem mention? Based on di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```A CD dey read by focusing a 780 nm wavelength (near infrared) semiconductor laser wey dey inside the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light dey reflect. By measuring the intensity change with a photodiode, the data fit dey read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser dey placed on top of a swing arm inside the disc tray of any CD player. This swing arm allow the laser to read information from the centre reach the edge of a disc, without having to interrupt the spinning of the disc itself.``` 