Jesus enters Jerusalem riding a donkey rather than a horse which signifies the peaceful nature of his entry. People are expecting a king and surrender themselves to his authority by taking their cloaks off and laying it on the ground. The Palm branches signify the expectation of a military victory of their king over the occupying Romans. Jesus is entering Jerusalem to bring Peace and forgiveness to the world by taking the sin of the world upon Himself - a Spiritual King. People are seeking a worldly and physical king.