Animation Blend Space
A blend space allows you to blend animations together without having to animate the transitions yourself
This is useful for idle/walking/running animations, the blend space allows you to cleanly transition
between the three(or however many) based on a parameter, in most cases it's your characters speed
There are two types of blend space, Legenacy 1D blend space (Right click Content drawer->Animations->Legacy->Blend Space 1D)
And Just Blend Space (Right Click content drawer->Animation->Blend Space)