[Brooks]

Here's a poorly drawn illustration which may clear up any confusion you might have.

Notice how the light rays under the soft light source strike the subject from an infinite number of angles. That's what causes the light to "wrap around " the subject. The light doesn't bend around the subject it comes from so many directions it more easily hits other areas on and around the subject. The light striking the subject from those infinite number angles and directions is what makes this light a "soft" light.

Notice how the light rays from the hard light source strike the subject from a very small number of directions and angles. Imagine that light source to be even smaller and farther from the subject. Then the only rays striking the subject would be parallel with very few light rays from any other appreciable angle. This organized, parallel arrangement of light rays is what makes this light a "hard" light.