Audiophile simply means a person how loves audio. This hobby has two main components: music and equipment, although the term itself also applies to high-quality recording and mastering techniques that an audiophile would presumably enjoy.
For those who seek perfection in musical reproduction, an audio system should sound as close as possible to the source material. The listener must be able to perceive nuances such as instrument placement, detail, "air", sound stage, timbre and transparency. And absence of "colorations" or other artifacts and distortions is essential.
In recent times, major advances have been made in digital audio, such that high-dynamic range 24-bit recordings, captured at high-resolution sample rates up to 384Khz, are now available. While digital audio has been disregarded as lacking in key respects by "analogue" audiophiles—who prefer vinyl records, turntables and tapes to digital files for their source materials—the recent development of ultra-low jitter and low phase noise technology such as the Audiophilleo has made the gap vanishing small.