If you change the value in the properties file, you don't need to recompile the java class. So, it makes the application easy to manage. It is used to store information which is to be changed frequently. 

BlockingQueue is an interface which extends the Queue interface. It provides concurrency in the operations like retrieval, insertion, deletion. While retrieval of any element, it waits for the queue to be non-empty. While storing the elements, it waits for the available space. BlockingQueue cannot contain null elements, and implementation of BlockingQueue is thread-safe.

public interface BlockingQueue<E> extends Queue <E>  

Here are the differences:

The differences between the Collection and Collections are given below.

• The Collection is an interface whereas Collections is a class.
• The Collection interface provides the standard functionality of data structure to List, Set, and Queue. However, Collections class is to sort and synchronize the collection elements.
• The Collection interface provides the methods that can be used for data structure whereas Collections class provides the static methods which can be used for various operation on a collection.

The differences between the HashMap and TreeMap are given below.

The differences between the HashSet and HashMap are listed below.

The differences between the Set and Map are given below.

The HashSet and TreeSet, both classes, implement Set interface. The differences between the both are listed below.

The List and Set both extend the collection interface. However, there are some differences between the both which are listed below.

Here are the differences: