What is the difference between class declared with static and final in PHP?

In PHP, the `static` and `final` keywords are used in different contexts and have distinct meanings.

 `static` Keyword:

1. **Static Properties and Methods:**
   - When used within a class, the `static` keyword is typically used to declare static properties and methods. Static members belong to the class itself rather than to instances of the class. They can be accessed using the class name without creating an instance of the class.

2. **Example:**
   ```php
   class Example {
       public static $staticProperty = 'Static Property';
       
       public static function staticMethod() {
           return 'Static Method';
       }
   }

   // Accessing static property
   echo Example::$staticProperty;

   // Calling static method
   echo Example::staticMethod();
   ```

### `final` Keyword:

1. **Final Classes:**
   - When used before a class declaration, the `final` keyword indicates that the class cannot be extended. In other words, it prevents other classes from inheriting from the declared class.

2. **Final Methods:**
   - When used before a method declaration, the `final` keyword indicates that the method cannot be overridden by subclasses.

3. **Example:**
   ```php
   final class FinalClass {
       // Class definition
   }

   class Subclass extends FinalClass {
       // This will result in an error, as FinalClass cannot be extended
   }

   class Example {
       final public function finalMethod() {
           // Method definition
       }
   }

   class Subclass extends Example {
       // This will result in an error, as finalMethod cannot be overridden
   }
   ```

 Differences:

1. **Scope:**
   - `static` is primarily used within a class to declare static properties and methods. It has no relevance when applied to a class declaration.
   - `final` is used to declare a class as non-extendable or to prevent the override of a method. It doesn't apply to properties directly.

2. **Inheritance:**
   - The `static` keyword is not related to inheritance but rather defines properties and methods that are shared at the class level.
   - The `final` keyword is specifically used to control inheritance, either by preventing a class from being extended or by preventing a method from being overridden in subclasses.

3. **Usage:**
   - Use `static` to declare properties and methods that are shared across instances of a class.
   - Use `final` to prevent further extension of a class or to prevent overriding of a method.

In summary, `static` is related to the concept of class-wide properties and methods, while `final` is related to controlling the inheritance and extension of classes and methods. They serve different purposes and are used in different contexts within PHP class definitions.