Broad spectrum CBD begins as a full spectrum extract with all of hemp's terpenes and cannabinoids intact, before it is sent through a refinement process to remove the THC compound. Broad spectrum CBD is full spectrum CBD without the THC.
Why should I pick Broad Spectrum over Full Spectrum? The main difference is that full spectrum extracts may contain trace amounts of THC (under 0.3%), while broad spectrum extracts have the THC completely removed.
Aside from this difference, broad spectrum hemp and full-spectrum hemp are extremely similar.