This example is going to surprise you but an angel, or no living entity, is closer or more important to God than any other. And just like all things in God's creation, there is in fact an order to the population of angels. The higher the order or level, the more powerful the Angel. These angelic beings can advance from one level to the next. And similar to our advancement on the job and school, heavenly angels earn advancement based on their good deeds and their bodies of experience.
The first group we'll discuss is more or less the freshman of the group and they do not have wings. They visit us most often to protect and rescue us from harm and danger. The arch angel is the sophomore of angelic beings. Consider arch angels the image makers. They have wings, headdresses and crowns that are often worn as badges of honor. It identifies their progress through the hierarchy. As they accomplish more and more, their wings show more silver and gold as they work toward the next level. Archangels are the messengers of God. Remember the Archangel Gabriel who told Mary she was chosen by God to carry His son Jesus?
The juniors are God's witnesses on earth. They are called the Cherubim and Seraphim. They are, in a sense, God's on-site reporters. The Cherubim and the Seraphim were the most magnificently and notably visible during the birth of Jesus when they all joyfully gathered to attend. The senior are the Thrones and Principalities, who are the most powerful of the angels. The Thrones are wisdom keepers and never descend to our dimension.

The Principalities do descend but only when God sends them and the situation is dire. Principalities can intervene at a potentially fatal moment in our lives, exclusively at God's direction. Only the gathering of God-sent Principalities and their immense power among the angels can create a miracle. Now, sit back and think of a time when an Angel showed up just in the nick of time. Remember knowing without knowing that there was a force greater than you that had made the impossible possible. Re-read what you've learned here about the hierarchy of an angel and just remember how they've helped you.