EDF was published in 1992 and stores multichannel data, allowing different sample rates for each signal.
The header contains some general information (patient identification, start time...) and technical specs of each signal (calibration, sampling rate, filtering, ...), coded as ASCII characters.
But EDF+ files also allow coding discontinuous recordings as well as annotations, stimuli and events in UTF-8 format.
EDF+ has applications in PSG, electroencephalography (EEG), electrocardiography (ECG), electromyography (EMG), and Sleep scoring.
The file extension "edf" may also stand for the ESRF data format, defined by the European Synchrotron Radiation Facility and frequently used for small-angle scattering data.