CollectionVsStreams

Difference between Collection API and Stream API
Collection API is in use since Java 1.2. Stream API is added to Java in version 8.

Collection API is used for storing data in different kinds of data structures.
Stream API is used for computation of data on a large set of Objects.

With Collection API we can store a finite number of elements in a data structure.
With Stream API, we can handle streams of data that can contain infinite number of elements.

Collection API constructs objects in an eager manner. Stream API creates objects in a lazy manner.

Most of the Collection APIs support iteration and consumption of elements multiple times.
With Stream API we can consume or iterate elements only once.




Difference between Iterator and Spliterator
Iterator was introduced in jdk 1.2 while Spliterator is introduced in jdk 1.8

Iterator is used for Collection API while Spliterator is used for Stream API

Iterator can be used for iterating the elements in Collection in sequential order
while Spliterator can be used for iterating the Stream elements in parallel or sequential order.


Differences between Java’s OLD Date API and Java 8’s Date and Time API
Earlier Date API was not thread safe while Java 8's Date and Time API is thread safe.

Earlier Date API was mutable while Java 8's Date and Time API is Immutable.

Earlier Date API defines months from 0 to 11 while Java 8's Date and Time API defines months from 1 to 12.