Aikido is a Japanese Budo, or martial way, that was developed by Morihei Ueshiba (O Sensei) from martial forms such as Daito-ryu Aiki-jujutsu and his spiritual experiences. He formulated its principles around the 1920s and also named the practice as Aikido: the way of harmonious spirit.
Aikido is sometimes referred to as one of the most philosophical or spiritual of martial arts. Morihei Ueshiba aimed to devise a way to defend oneself while protecting the attackers. On the one hand, Aikido practitioners need to establish strength and power and on the other: nonaggression. The goal is to overcome oneself instead of cultivating violence, expressed by Morihei Ueshiba as:
"True victory, final victory over oneself, here and now".
Different people connect to different facets of Aikido. Depending upon the practitioner, they take away:
Physical fitness: through a robust and athletic approach to enhance balance and coordination; strengthen ligaments, tendons and joints; improve musculature; and increase cardio-vascular health,
Self defence: since Aikido is fundamentally a system of self-defence comprising of unarmed techniques (joint locks & throws) and weapon techniques with Tanto (wooden knife), Jo (wooden stick), and Bokken (wooden sword) -- founded on traditional samurai martial methods,
Budo: the warrior's way, which, in contrast to Bujutsu - the science of war, is not only about the physical aspects of fighting but also about the development of the mind and oneself; where the emphasis is not on defeating an external enemy but on a way of life that is focused inward with the aim of conquering oneself.