The document discusses the difference between using the present continuous and "be going to" when talking about the future. The present continuous is used to talk about definite future arrangements that have already been decided on, like "I'm leaving in the morning." "Be going to" is used to talk about future plans and intentions that have not necessarily been set in stone, like "I'm going to fix the television tomorrow." Although sometimes interchangeable, generally the present continuous implies something has been arranged while "be going to" implies something is intended.