`Nested conditional statements` are when you have conditional statements inside other conditional statements. This is often done to provide more specific and detailed conditions to check.

For example:

``` javascript
let age = 25;
let country = 'USA';

if (country === 'USA') {
  if (age >= 21) {
    console.log('You are old enough to drink.');
  } else {
    console.log('You are not old enough to drink.');
  }
} else if (country === 'Canada') {
  if (age >= 19) {
    console.log('You are old enough to drink.');
  } else {
    console.log('You are not old enough to drink.');
  }
} else {
  console.log('Sorry, we do not have drinking age information for your country.');
}
```

In this example, there are two levels of conditional statements. The outer `if-else` statement checks the country, and then the inner `if-else` statement checks the age.

If the country is `"USA"`, the inner `if-else` statement checks if the age is greater than or equal to `21`. If it is, it outputs "You are old enough to drink." If it is not, it outputs "You are not old enough to drink."

If the country is `"Canada"`, the inner `if-else` statement checks if the age is greater than or equal to `19`. If it is, it outputs "You are old enough to drink." If it is not, it outputs "You are not old enough to drink."

If the country is not `"USA"` or `"Canada"`, it outputs "Sorry, we do not have drinking age information for your country."

Nested conditional statements can also be used with switch statements, and with multiple levels of nesting. However, it is important to keep them as simple and clear as possible to avoid confusion and mistakes.

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In the exercise below, select all conditional statements from `JavaScript`

Nested Conditional Statements