To know what you are being tested on (use: checklists or the syllabus)
To know where you can revise the content (use: revision guide, website, videos)
To check your understanding using suitable difficult questions (use: old exam papers or Exampro questions)
To practice your timing and exam technique (use: past papers)
These sites will offer videos mapped to the course. Choose the right one for your purpose: first time revision, recap at the later stages or the need to answer questions.
AS Level Only:
30 minute videos
Detailed and better for first time revision where you need gaps filled
AS and A2:
5-10 minute videos
The entire course in tiny, fragmented sections.
Great if you need something very specific.
If you just need another perspective from someone who is going to explain a concept, without the constraints of the syllabus, these guys are your go to.
Bozeman recaps in an information dense but highly efficient manner the more advanced topics.
Professor Dave can often explain concepts in a visual way, with clarity and maths.
Physics and Maths Tutor have bundled questions together (old exam questions) based on sub-topics.
The mark schemes are provided, and written revision notes in case you wish to look something up.
You will have 5 revision lessons on each side of the course. The focus will not be content, but skills and how to tackle the trickier question styles.