There are differing opinions to whether angels and guides are the same thing. I believe that they are totally separate entities.
Angels
An angel to me is usually an evolved spirit that has never touched the earth plane and deal with the higher stages of our spiritual enlightenment. They become involved when there are grave or very serious matters that have to be influenced or when guidance is required that involves humanity or the earth as a whole. I do believe that at times angels do visit the earth plane but that would be only in times of dire emergency, or where it is essential that the angel reveals itself to bring hope and encouragement to enable the person to go on to achieve something momentous.
Guides
A guide is the spirit of a person that has lived on the earth plane. They have decided that they wish to help and assist people within this existence in their daily lives or on their spiritual pathway. The guides can appear in may different forms but I believe that they appear in a form that is most acceptable to you, but this may not be their true essence. Guides come and go as they learn from you and you from them. You do whoever have one guide that will stay with you from birth to death and that is your gatekeeper. If you are developing your spiritual gifts then you will have a guide that will assist with you mediumship, one for healing and another for trance work. These guides form a team to enable you to learn and move forward in your development.