Audio format refers to the method used to import audio data from the Internet or audio CDs to a computer, to save as an audio file.

Common formats include MP3 and WMA, etc.

MP3: MP3 (MPEG-1 Audio Layer3) is a common audio compression technology developed by the MPEG working group of the ISO (International Organization for Standardization).

MP3 can compress audio files to about 1/10 the size of standard CD audio files.

WMA: WMA (Windows Media Audio) is a common audio compression technology developed by Microsoft Corporation. The WMA format produces the same sound quality as that of the MP3 format with a smaller file size.

Certain music files or video files, etc., that you purchase from a music download service site, etc., may have access control technologies applied, such as encryption, to limit usage and duplication of the material, in accordance with copyright laws.

Bit rate refers to the amount of data used to store each second of audio, expressed in kbps (kilobits per second), such as 64 kbps. Generally, higher bit rates provide better sound quality, but require more storage space for the same length of audio.

Generally, higher bit rates provide better sound quality, but require more storage space for the same length of audio, so you can store fewer songs on your Walkman.

Lower bit rates enable you to store more songs, but at a lower sound quality.