The order of angels is made up of the angels of the Lord and the angels of Satan. The role of the former is to praise and worship God, execute His will, pass on the divine messages, serve the believers and to especially represent and protect children.
They take part in carrying out God's plans and promises (such as proclaiming the redemption, fighting against hostile forces on the side of God's people, execution of God's judgment). The Bible forbids the worship of angels.
The Holy Scripture lists four main orders of spiritual beings: thrones, dominions, rulers, authorities (NIV).