The style of Aikido which is the most common around the world. It is now lead by Moriteru Ueshiba ,the grandson of Morihei Ueshiba. It is extremely hard to describe how it differs from other aikido styles in words. But if you a have scale with Tomiki and Yoshinkan Aikdio being the least spiritual and Ki Aikido being the most. Aikikai lies in the middle. Stressing both the physical and the spiritual aspect. And applying atemi as needed.This means that the techniques are neither very direct nor too flowing. By the way, Aikikai is not the most traditional style of Aikido. The is is usually considered to be Iwama-ryu.