"Unlike the phone system, which is engineered around an application, the Internet layered model allows you to, in essence, separate applications from infrastructure"

This quote by Michael K. Powell is describing the differences between the phone system and the Internet. The phone system is created around a specific application, suggesting that it is customized to a specific purpose. On the other hand, the Internet is developed using a layered design, which enables applications to be separated from the infrastructure. This indicates that the infrastructure can be utilized for several applications, as opposed to the phone system which is restricted to one. This layered model also allows for more versatility and scalability, as the infrastructure can be gotten used to accommodate various applications. This makes the Internet a much more flexible and powerful tool than the phone system.