The angels were mentioned in Quran in around 88 places. Hundreds of Hadeeths narrated by Ahlul Bayt (AS) from the Prophet Muhammad (SAWA) did mention the angels. The angels have degrees and different duties. The four main angels are Israfil, Jabrael, Mikaeel and Izraeel.
'The duties of the angels are in very big variety. You can find more details in the books of Hadeeth like Biharul Anwar.