The main difference between full-spectrum and broad-spectrum CBD is the compounds they contain. If a CBD product contains several naturally occurring cannabis plant extracts, such as terpenes and other cannabinoids — including up to 0.3% THC — it is full-spectrum CBD.
The difference between broad spectrum, full spectrum and CBD isolate is simply the chemical compound content found in each of the products. Full spectrum CBD contains all of the cannabinoids and other plant compounds. Broad spectrum CBD contains all cannabinoids and plant compounds other than THC.