Duties of Angels

Angels have various duties, with each having a well-defined role. "And there is not any among us, except that he has a known position. And we are indeed the ones who are arranged in ranks for prayer. And we are indeed the ones who glorify Allah"
(Sura Al-saffat, 37:164-166)

Angels thus teach us the benefits of specialization. So, in the Islamic society, some members musts specialize in the Qu'ran and its sciences, some in Hadith sciences, others in medicine, still others in agriculture and soon and so forth, so that the Muslim community becomes efficient and well balanced.  Similarly, in the home, the responsibilities are divided. While the man is responsible primarily for supporting the family financially, the woman has an important role in upbringing the children, although she is by no means confined to only this task.

Only Allah (SWT) knows all the details and roles of all the angels: "And none know the hosts of your Lord except He"
(Sura Al-Muddathir, 74:31)

Nevertheles, He has told us about some of these angels through the Qu'ran and Sunnah.

The names and Roles of some Angels
Only few angels are mentioned by name in the Qu'ran and Sunnah. Others are mentioned either by specific names or by roles or their general nature of serving and worshiping Allah (SWT).

Among those are:

Jibreel (angel Gabriel), This is the most distinguished of the angels, and is intrusted with carrying revelation to the Prophets. This includes briging the Qu'ran to Prophet Muhammad (SAW) which is referred to in the following:

"Verily this is a Revelation from the Lord of the Worlds: with it came down the Spirit of Faith and Truth to thy heart and mind, that thou mayest admonish in clear Arabic tongue."
(Sura Al-Shu'ara', 26:192-195)

Angel Jibreel is also called "the Holy Spirit" as mentioned in the Qu'ran

"Those Messengers we endowed with gifts, some above others: To one of them Allah spoke; others He raised to degrees (of honour); to Jesus, the son of Mary, we gave Clear (Signs) and strengthened him with the Holy Spirit. If Allah had so willed, succeeding generations would not have fought among each others, after clear (signs) had come to them but they (chose) to wrangle, some believing and others rejecting. If Allah had so willed, they would not have fought each other; but Allah fulfilleth His plan."
(Sura Al-Baqarah 2:253)