What is the difference between Collection and List in Java?

Question

What is the difference between Collection and List in Java? When should I use which?

Answer 1

Collection is a high-level interface describing Java objects that can contain collections of other objects. It's not very specific about how they are accessed, whether multiple copies of the same object can exist in the same collection, or whether the order is important. List is specifically an ordered collection of objects. If you put objects into a List in a particular order, they will stay in that order.

And deciding where to use these two interfaces is much less important than deciding what the concrete implementation you use is. This will have implications for the time and space performance of your program. For example, if you want a list, you could use an ArrayList or a LinkedList, each of which is going to have implications for the application. For other collection types (e.g. Sets), similar considerations apply.