Div Model vs Div Growth Model

When do I use the Div Model and when do I use the Div Growth model to attain the Cost of Equity? My question bank is using them interchangeably and I am a bit confused. Sometimes they just use D0/P0 even though they talk about growth and other times they account for the growth and use D1/P0 +G which i understand is the same as D0*(1+G)/P0