This video is an explanation of principles of Kote Gaeshi which should be easily accessible to beginners.
Aikido is a modern Japanese martial art developed by Morihei Ueshiba as a synthesis of his martial studies, philosophy, and religious beliefs. Aikido is often translated as “the way of unifying (with) life energy” or as “the way of harmonious spirit”. Ueshiba’s goal was to create an art that practitioners could use to defend themselves while also protecting their attacker from injury. Read more about Aikido here on Wikipedia.