They are invisible to us. They are neither male nor female.
They do not disobey Allah and do not commit acts of sin.
They are always busy in doing their task, assigned to them by Allah.
The angels are many . No one except Allah know their exact number.
We, however, know that there are many angels.
Four of them are very famous and close to Allah.
The first one of them is Angle Jibra'il (Gabriel) who brought Allah's Scriptures, Messages, and Commands to the prophets.
The second is Angle Israfil who will blow the trumpet on the Day of Judgement.
The third is Angle Mika'il who is appointed to manage the rains and to deliver livelihood to Allah's creatures.
The fourth is Angle Izra'il, responsible for ending the life of Allah's creatures.