Flow Control is the way your program can make decisions while its running. Let's look at an example!

boolean isRobotOn = true; 
if (isRobotOn) {
    System.out.println('Robot is on!');
}

This is an if statement, and the code inside the block is only ran if the expression resolves to boolean value that is true. Because the expression of isRobotOn resolves to true, the code inside the if statement block is ran, printing out "Robot is on!" to the console.
Let's look at some other expressions:

boolean isRobotOn = false;
int robotAge = 4;
if (!isRobotOn) {
    System.out.println('Robot is off!');
}

if (robotAge == 4) {
    System.out.println('Robot age is 4!');
}

Here, we can see the not operator and the equals operator. The not operator resolves to the inverse of the boolean value that comes after it, so because isRobotOn is false, its is inverted to true, so the code inside the block is ran. The equals operator resolves to true only if both side of the operator are equivelent to each other.

What if you wanted to do something if the if statement failed? You would use an if else block! Here is an example of one:

boolean isRobotOn = false;

if (isRobotOn) {
    System.out.println('Robot is on. Yay!');
} else {
    isRobotOn = true;
}

Here we can see the use of a new keyword, else, which sits right after the closing curly bracket of the if statement and is followed by another code block. This code block is only ran if the if statement doesn't activate (such as the expression resolving to false). But wait, Theres more! You can also check for another condtion if the if statement fails by using an else if block!

boolean isRobotOn = false;
int robotAge = 4;
if (isRobotOn) {
    System.out.println('Robot is on. Yay!');
} else if (robotAge == 4) {
    System.out.println('Robot is 4 years old!');
}

Before we get to the table, we need to talk about the difference between a unary and a binary operator. A unary operator only operates on one value, and the value usally proceeds the operator (such as !isRobotOn). A binary operator operates on 2 values, one on the left hand side of the operator and one on the right hand side (such as 2 + 2); Given that, here is a table of the different types of boolean operators: