With all the main programming tools in place, we can start talking about Java as a language. The language syntax is defined by Java Language Specification, which you can find on https://docs.oracle.com/javase/specs. Don't hesitate to refer to it every time you need some clarification. It is not as daunting as many people assume.

All the values in Java are divided into two categories: reference types and primitive types. We start with primitive types and operators as the natural entry point to any programming language. In this chapter, we will also discuss one reference type called String (see the String type and literals section).

All primitive types can be divided into two groups: the boolean type and the numeric types.