Depending on the offence, penalty points and disqualifications are valid for either 3 or 10 years, but they remain on your record for an additional year. Please see the link in Related Information which tells you how long points will remain on your driving record.
If you apply for a driving licence at the age of 17, any points you received as a 15-year-old will be shown on your driving record - you can view your driving record via the link in Related Information.
If you acquire further points on your licence so that the number reaches 6 or more within 2 years of passing your test your licence will be revoked and if you obtain 12 points with a 3 year period, you will be disqualified.