This cheat sheet, from Princeton University's Introduction to Programming in Java course, makes a great reference for the basics you need to know, like structure, input/output, data types, and ...

How to recognize and use array and list data structures in your Java programs. Which algorithms work best with different types of array and list data structures. Why some algorithms will work ...

All of the data structures we’ll look at in this series are aggregates. Containers. Anything from which data items are stored and retrieved could be considered a data structure.