The main purpose is to allow students to catch up material they have missed – which is why there are often notes included in them for students to take down – or revise before an assessment.
This page does not have the videos embedded, to save on download time and make the page easier to navigate. Instead the links open a new page in YouTube (or similar).
Go here for the embedded version of my videos
The Maths OSC channel at YouTube
has quite a few relevant videos on the skills required for this year.