What's the difference between product innovation and process innovation?

Product Innovation
- Development of a totally new product or improved product or services. The product innovation is limited to the outcome of a process, which is a product.

Process Innovation
- Finding a novel way of achieving an output which was traditionally done in a different way. In the process innovation, the final product is not touched, but the method of bringing out the product is improved. The improvement could be due to use of new techniques, equipment etc
eg - The Pilkington glass method