Capture mobile records all audio in the CAF (Core Audio Format). This is an Apple format that allows not only audio to be captured in the file but also other helpful data about the way the audio was recorded. The CAF file format is essentially a container that stores the actual audio file and any meta data that may be relevant to that audio. The audio format that Capture records within it's CAF files is Apple Lossless Audio Codec or ALAC. This is Apple's own version of a lossy compression format. Lossless audio formats contain the same data as it's full size equivalent so there is no loss of audio quality when using the ALAC audio format. Using the ALAC format within the CAF files allows for more audio to be recorded on your device as well as provide fast wi-fi transferring of Capture sessions. Once transferred to Studio One, Capture CAF files can be converted to any other format if desired and retain it's full quality.
For more information about Core Audio Format (CAF) please visit Apple's site
For more information about the ALAC audio file format please visit here:
http://en.wikipedia.org/wiki/Apple_Lossless