As Rollo states, A-levels (or, to give them their full title, GCE A-Levels) remain the same. However, there are now two stages. After the first year of study, students now take AS level examinations. They can either stop at that point or continue for another year for the A2 examinations. If they do so, 50% of the AS result and 50% of the A2 result are combined to give an overall A-level result:
http://www.direct.gov.uk/en/EducationAndLearni ng/QualificationsExplained/DG_10039018
GCSEs replace
both GCE O-levels and CSEs. Grades A* to C are equivalent to O-level passes. Grade C also matches a Grade 1 pass at CSE. Grades D to G are equivalent to the remaining CSE grades:
http://www.direct.gov.uk/en/EducationAndLearni ng/QualificationsExplained/DG_10039024
Chris