What is Shaping?
Shaping (often know as rate limiting) is the term used to describe the slowing down of your internet connection. This will occur if you have exceeded your monthly download quota.
(Plans with peak and offpeak quotas will be shaped for both quotas if either quota is reached)

The main benefit of Shaped plans is that you will never have any excess usage charges. You simply pay a flat rate per month, no matter how much you download, or how much time you spend connected.