-Card input: Card input refers to the way to realize audio input by inserting storage devices such as SD card, TF card and U disk. Users can store audio files in the storage device, and then insert the storage device into the corresponding card holder to play. This way can simply and conveniently play the audio files in the storage device.
-CD input: CD input refers to the way to realize audio input through CD disk. The user inserts the CD into the device, and then the device will read the audio content on the CD and play it. In the past, CD input was a main audio input method, which could bring high-quality audio playback effect. However, with the development of digital audio, CD input is gradually replaced by other digital audio input methods, such as USB input and Bluetooth input.
Generally speaking, card input is suitable for playing audio files in storage devices, while CD input is realized through CD disks. Which input method to choose depends on the support of the equipment and the needs of users.