Derived from the Greek word angelos which means “messenger”, angels have been regarded in almost every religion as messengers of God. They have been represented in classical art and iconography in both male and female forms bearing wings. In Christian theology, angels have been classified into hierarchies into at least three levels. To the highest level belong the cherubim, seraphim and thrones. Of the middle order are dominions, virtues and powers and lowest are the archangels, angels and principalities.
Although loosely based on the Judaic conception of Angels, the Christian model nevertheless changed the hierarchy and added a few others. For example, in rabbinic Judaism Archangels are the highest of which there are seven, followed by Angels which are further divided into higher and lower orders. Included in the higher order are the cherubim and seraphim.
The point in all this is the realisation that these beings are messengers. What this means is that they carry out the Will of God and indeed swing in this Will hence the wearing of pinions as a symbol of this unconditional swinging. Generally, archangels are meant to be higher in their activities than angels. Angels are to be found at all levels of Creation and they are indeed dispensers of power, virtues and so much else. This is the strict meaning of the term Angel and it is probably better at this stage to stick to this to avoid confusion. Creation has myriads of beings who are servants of God and carry out His Will unconditionally.