What is the difference between 'Networking' and 'Teamwork'?

During a workshop for employees of a property development company yesterday I outlined my definition of networking:

"Networking is the collaboration with others to enhance our potential beyond that which we could achieve on our own."  One of the delegates on the workshop asked me, "Isn't that the same as teamwork? What is the difference between networking and teamwork?" It's an interesting question. Whenever I speak to employees of larger companies there is as much focus on networking...