Explain the difference between 'Option', 'Some', and 'None' in Scala.

In Scala, `Option`, `Some`, and `None` are used to handle optional values and represent absence of a value. They are part of the Scala standard library and provide a safer alternative to handling null values.

Here are the differences between `Option`, `Some`, and `None`:

1. `Option`: `Option` is a container type that represents an optional value. It can either contain a value (`Some`) or signify the absence of a value (`None`). It is a generic type with two subclasses: `Some` and `None`.

2. `Some`: `Some` is a subclass of `Option` and represents a container that holds a non-null value. It is used when a value is present.

3. `None`: `None` is a subclass of `Option` and represents the absence of a value. It is used to indicate that no value is present.

4. Safety : Using `Option`, `Some`, and `None` helps in writing safer code by explicitly handling the absence of a value. It avoids null pointer exceptions that are common when working with nullable references.

5. Functional Composition : `Option` provides methods that allow for safe and concise composition of operations on optional values, such as `map`, `flatMap`, and `getOrElse`.

6. Pattern Matching : Pattern matching is often used with `Option` to handle the different cases of presence or absence of a value. It provides a convenient way to extract values from `Some` and handle the `None` case. Here's an example to demonstrate the usage of `Option`, `Some`, and `None`:

val someValue: Option[String] = Some("Hello, World!")
val noneValue: Option[String] = None

def printValue(option: Option[String]): Unit = option match {
  case Some(value) => println(value)
  case None => println("No value")
}

printValue(someValue) // Output: Hello, World!
printValue(noneValue) // Output: No value​

In this example, `someValue` is an `Option` holding a `Some` value with the string "Hello, World!", while `noneValue` is an `Option` holding a `None` value.

The `printValue` function takes an `Option` as an argument and pattern matches against it. If the `Option` is a `Some`, the value is extracted and printed. If the `Option` is a `None`, it prints "No value".

By using `Option`, we can handle the cases where a value may or may not be present, explicitly indicating the absence of a value and avoiding null-related issues.

Using `Option` and its subclasses (`Some` and `None`) promotes a more functional and safer approach to dealing with optional values in Scala, improving code clarity and reducing the likelihood of runtime errors caused by null references.