In a nutshell, Freelance Web Development. More specifically:
I work with your team adding skills that aren't readily available.
I've built applications and sites from the ground up. I work with designers who take care of the look and feel aspects of the project. I've also successfully worked with and managed teams of developers and designers.
I can use my own libraries, off the shelf ones, or existing custom-built solutions.
I've taken over projects and finished, built onto or even rebuilt them where appropriate.