"Let me tell you about commands (statements) and code blocks. This is really simple stuff. A method body consists of commands, or statements. Each command ends in a semicolon."

Java-университет
Examples of commands:
1 
String s = "Name";
2 
System.out.println(1234);
3 
return a + b * c;
4 
throw new RuntimeException();
5 
;

"A code block consists of several commands combined using curly brackets. A method body is a code block."

Examples:
1 
{}
2 
{
     throw new RuntimeException();
 }
3 
{
     return null;
 }
4 
{
     System.out.println(23);
     System.out.println(1);
     System.out.println(14);
 }

"The following rule is valid in almost any situation: wherever you can write one command, you can also write a code block. We will see examples of this in subsequent tasks."