What can interoperable blockchains achieve?

Before going further and looking at how to achieve blockchain interoperability, we need to know what kinds of things that interoperable blockchains can achieve. There are obviously many use cases for interoperable blockchains, but we will be looking at the use cases that interoperability between blockchains mostly aims to achieve. It may achieve one or more of the following use cases:

• Portable assets: Moving assets back and forth from one blockchain to another. These are also called one-to-one pegs or two-way pegs. 
• Payment-versus-payment and payment-versus-delivery: These are technically known as atomic swaps. When two users are exchanging assets that reside in two different blockchains, a guarantee is needed, stating that either both transfers happen or neither does. For example, if one blockchain holds digitalized...