Sample rate is the number of audio samples (measurements of audio waveform amplitude) taken per second, measured in Hertz (Hz) or kilohertz (kHz). Higher sample rates can represent higher audio frequencies. According to the Nyquist theorem, a sample rate must be at least twice the highest frequency being recorded — human hearing tops out at approximately 20 kHz, which is why 44.1 kHz became the CD standard (giving headroom above the 40 kHz Nyquist threshold).
Common sample rates: 44.1 kHz (CD audio, standard for music, supported everywhere), 48 kHz (video/broadcast standard, used in film and TV production, standard for video files), 96 kHz (high-resolution audio, professional recording), 192 kHz (ultra-high-resolution, rarely justified). The difference between 44.1 and 96 kHz is inaudible in double-blind tests for most music, but higher rates provide more headroom for processing.
For music production: record at 48 kHz (matches video standards) or 44.1 kHz (matches distribution formats), use 96 kHz only if your workflow and hardware benefit. For distribution: 44.1 kHz MP3/FLAC for music, 48 kHz AAC for video/podcasts. FileCurve preserves the original sample rate when compressing audio.