Connections & formats
16-bit/44.1 kHz
Also called CD quality, Red Book, 44.1 kHz
16-bit/44.1 kHz is the resolution of the compact disc: each sample has 16 bits of depth and there are 44,100 samples per second per channel. It is the baseline most streaming services call "lossless" or "CD quality".
The sample rate of 44.1 kHz captures everything up to about 22 kHz, past the limit of adult hearing. The bit depth of 16 bits gives a theoretical dynamic range of about 96 dB, which is more than a quiet room allows you to use.
A ripped CD, a FLAC download or a lossless stream at this resolution contains the same audio data. Formats above it, such as 24-bit/192 kHz, add headroom that matters in a studio but whose audible benefit on playback is disputed.
The odd number comes from early digital recorders that stored audio on video equipment; it was kept for the CD and has stayed the consumer standard since.