What is a block of Code?

Answer 1

Line of code:

System.out.println("Hello");

Block of code (example):

if(1+1==2) {
System.out.println("You");
System.out.println(" Genius!");
}

Answer 2

Adding to what HonFu said , Lines of code which are executed to complete one specific task.

Answer 3

Block of codes MEANS code inside of the curlybraces
{
//your codes goes here
}