PCM (Pulse-Code Modulation)
Definition
The standard method for digitally representing analog audio. PCM works by sampling the amplitude of the analog signal at regular intervals (the sample rate) and encoding each measurement as a binary number (the bit depth). WAV and AIFF files contain uncompressed PCM audio.
In Simple Terms
The fundamental method behind all digital audio—it turns sound into numbers by measuring the volume thousands of times per second. Every WAV and AIFF file on your hard drive is PCM audio. It's the raw, uncompressed form of digital sound.
In Practice
A WAV file at 24-bit / 48 kHz contains uncompressed PCM audio — 48,000 amplitude measurements per second, each encoded at 24-bit resolution. This is the foundation of all digital audio workflows.
Common Confusion
PCM is not a file format — it is an encoding method. WAV and AIFF are containers that store PCM data. FLAC compresses PCM data losslessly. MP3 and AAC use fundamentally different encoding approaches that do not store raw PCM.