So here's an animation of a walking dude. I created a skeleton of movable joints and then attached the body parts to the skeleton. Then I can move the joints around and the body parts will follow suit. I used a technique called forward kinematics to animate the body. It is called this because for example if I rotate the upper arm, everything down the chain ending at the hand will rotate the same amount. Things done at the root will move forward down the chain. It's easy to grasp but can take a lot of work because you have to rotate each part yourself.