Can you explain the differences between a connected and an unconnected lookup and when you should use each of them in a data migration?

This question asks you to compare two similar but different terms and to discuss when to use them in data migration. This is a typical operational question which starts with a definition and then asks you to describe how you would apply it. As a seasoned data migration operator, you should be able to answer this question easily.

"The two types of lookups are called connected and disconnected. A connected looked up is used for mapping and will return multiple values. It is called connected because it can be tied to another transformation. On the other hand, and unconnected lookup is used when it cannot be connected to another transformation. It returns a single value, but it is reusable."