Divergence is generally measured on the RSI and limited to finding either:
1. higher highs on the price and lower highs on the RSI (bearish divergence) 2. lower lows on the price and higher lows on the RSI (bullish divergence)
Continuous Divergence (CD) does two things differently. Firstly, it uses the MFI as its primary source of data, due to its volume component giving it higher accuracy. Secondly, it doesn't measure discrete divergence - i.e. between peaks and troughs - but rather a continuous divergence measurement.
Essentially it is measuring at any given time, the correlation between the price and the MFI. This is smoothed with a moving average (configurable) to get cleaner lines.
CD is used to detect both a slowing down of momentum on the current trend, and a reversal of trend due to changing momentum.