Graduated Access simply means that as you pass the homework and any tests, you will be given access to the next lesson and all associated content, if you subscribed to a block of lessons, or a Module etc. You will also be able to go back and refer to the previous lessons content (in case you need to brush up and view the handouts and the Video Instruction).
The reason we do this, is the lessons are best understood going in sequence. Years of experience has shown that when students did not have their previous lesson down, or the homework completed, they experienced frustration and confusion on the lesson following, because they did not have the foundation set to understand the next section.
We really want our students to succeed!