In CSS, there are different position values that you can use to control how an HTML element is positioned on a web page. These include:

• static: This is the default position value for HTML elements. Elements with a static position are positioned based on the normal flow of the document.

• relative: Elements with a relative position are positioned relative to their normal position in the document. You can use the top, bottom, left, and right properties to move the element from its normal position.

• absolute: Elements with an absolute position are positioned relative to the nearest positioned ancestor element. If there is no positioned ancestor, the element is positioned relative to the initial containing block (usually the body element). Like with relative positioning, you can use the top, bottom, left, and right properties to move the element from its normal position.

• fixed: Elements with a fixed position are positioned relative to the viewport (the browser window itself) and will not move even if the page is scrolled.

You can read more about CSS positioning at https://www.w3schools.com/css/css_positioning.asp.

CSS positioning allows styling of HTML elements by defining their position relative to the document, or a containing element. CSS positioning can be static, relative, absolute, and fixed.

Static: The static position is the default position for HTML elements. This sets the elements in their natural positions and no special positioning instructions are applied.

Relative: The relative position lets you position elements relative to their normal, static position. The top, right, bottom, and left properties define the distance from the elements original position.

Absolute: The absolute position takes elements out of the page flow and positions it at an exact spot relative to its containing element. The top, right, bottom, and left properties define the distance between the element’s containing block and the element itself.

Fixed: The fixed position is a combination of absolute and relative positioned elements. It allows you to position an element relative to the viewport, so that the element is always in the same place, even when the page is scrolled. The top, right, bottom, and left properties define the distance between the element and the viewport.

Example of CSS positioning:

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div {
 position: relative;
 top: 20px;
 left: 30px;
}

In the example above, the div is positioned relatively 20px from the top and 30px from the left of its original position.

A class in JavaScript is a type of object that provides the ability to group properties, methods and functions together into a larger structure. A class can be used to create many instances of the same type of object, and each instance can maintain its own set of data. Classes in JavaScript are defined using the class keyword and can include constructors, static methods and prototype methods.

Example:

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class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  sayHello() {
    console.log(`Hello, my name is ${this.name} and I am ${this.age}`);
  }
}

const person1 = new Person('John', '21');
person1.sayHello(); //prints 'Hello, my name is John and I am 21'

Reference: MDN Web Docs - Classes - JavaScript