Mudabbiraat is one of the angels mentioned in the Quran. They are the angels who arrange the Commands of Allah between Allah and His creation. Believing in angels is one on the Six pillars of Eeman.
One must believe that the angels are from the creation of Allah; no one knows their exact number except Him. They are from the unseen world. Allah created them to worship and obey Him. They carry out all of Allah’s orders, from administration, observation, guarding and protecting the universe as well its creatures, all according to Allah’s Will and Order.
Allah spoke about them in Quran: And by those angels who arrange to do the Commands of their Lord, (so verily, you disbelievers will be called to account). Quran Surah An-Nazi'at 79:5
The angels are not partners, associates, or rivals with Allah, nor are they His children; but one must still respect and love them. Allah says: "And they say: ‘The Most Beneficent (Allah) has begotten a child [from the angels].’ Far removed is He from every imperfection! They (the angels) are but honored slaves. They speak not until He has spoken, and [then] they act on His Command." Quran Surah Anbiya 21:26-27
They spend their time worshipping and obeying Allah, glorifying Him and praising Him. Allah says: "They (i.e. the angels) glorify His praises night and day, (and) without slackening (to do so)." Quran Surah Anbiya 21:20 
The angels were created from light. The Prophetﷺsaid: 'The angels were created from light, the Jinn were created from a smokeless flame of fire, and Adam was created from what was described to you (black dry clay).' Sahih Muslim 2996
A Muslim must believe specifically in all the angels named and/or described in the Qur'an and the ahadith: