What is the difference between humans and angels?

It is not reliable to let people tell you what the bible says. Many people will make up stuff because they don't know what it says, and many will make up stuff because they wish it would not say what it says. You just have to read it for yourself. Read a chapter of Proverbs every day. Proverbs has 31 chapters so you can keep your place by just looking at a calendar. There is no religion or nothing in Proverbs and you don't have to believe anything. Just read to find wisdom. When you are comfortable with that, then read the bible from Romans to 2 Thessalonians over and over until you start to remember what it says. That is the part that applies to Christians. Here is a book to help you to understand the bible. It's a free download and you can get a hard copy at any bible book store.
www.philologos.org/__eb-htetb/ "How To Enjoy The Bible"

By reading the bible we find a lot of things that surprise some people. Many people think angels are female, have blond hair, and sing. The bible always describes angels as "a man" and they never sing. The bible does not mention any angel committing a sin. Sin, singular, is the absence of spirit. Sins, plural, are mistakes such as throwing a dart and missing the mark. An angel is a spirit, so "sin" does not apply. Sin is a worldly thing. John 3:6 "That which is born of the flesh is flesh; and that which is born of the Spirit is spirit."

Angels are powerful spirit creatures, created by God long before humans were created. They were not made with the ability to reproduce their own kind but were created individually. In the future they will support Jesus in fighting the battle of Armageddon. Revelation 19:14,15

Humans are real; angels are imaginary. Humans are seen when we are awake, angels are seen when we dream. Humans are a manifestation of God on earth; angels are a creation of our imagination, originating from the thought of God in the skies. Therefore, it is up to us, to go in quest of realizing what we want in life. Do we want to seek God in a human being? Then we must realize that the kingdom of God is within every human being. God lives in the temple of our heart. If we want to believe certain scriptures which talk of angels in the sky, if we want to dream that after our death, angels will take us and fly us to a distant heaven, then we can continue to believe in this mythology, and believe in Santa Claus giving us gifts, when in reality, our parents are putting them under the Christmas tree. It is for us to overcome our ignorance and realize the Truth.