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 ...

This tutorial series is a beginner’s guide to data structures and algorithms in Java. You’ll learn: How to recognize and use array and list data structures in your Java programs.

In contrast, a data structure is a concrete implementation of one or more ADTs, similar to how Java classes implement interfaces. Examples of ADTs include Employee, Vehicle, Array, and List.