Gates was a programmer, and Jobs was not. But because of that, I think Jobs showed more of a pure form of an innovator.
- What Gates did = innovation + engineering
- What Jobs did = innovation
People often are very curious about what an innovator does. I think human beings still have a primitive tendency to associate work with something material. An 'idea' does not feel real. It's a part of explanation why people paid for books and newspapers, but won't pay for digital contents.
To simplify, an innovator creates ideas. It helps, often greatly, for an innovator to have the skills to build the product him/herself, but that's not the core of the job. Gates was innovator + engineer at MS, but with TerraPower he is probably just a pure-form innovatoand.
By the way, Gates is less associated with innovation, but Jobs once said Gates pretty much created a software industry, which I think makes a lot of sense.