Each unit carries its own assessment — typically a mix of online multiple-choice exams, written short-answer papers, and practical workshop tasks observed by your tutor or assessor. Those unit results are the gateway: every unit has to be passed before you go forward to the end-point.
The end-point assessment is run by NET. Under the current plan (ST0152 v1.2) it has three parts, each pass or fail: the AM2S practical (17 hours over no more than 3 working days, sat away from your normal workplace), an online knowledge test (45 questions in 90 minutes) and your behaviours, confirmed by your employer. The practical rewards speed and accuracy on things you have already done a hundred times on site, not last-minute theory cramming. See the electrician apprenticeship EPA guide.
Plan revision unit by unit using the linked pages above. Each gives you the topic checklist, the mistakes that cost marks, and a 5-step revision plan. For the end-point itself, start with the AM2 exam tips guide.