Core objects are independent of the client browser as opposed to browser objects.
The Array object as the name suggest, is used to create arrays. It has many methods to add, delete or extract elements from an array and sort them.
The Boolean object is used to create Boolean values. Elements with two states: true and false.
The Date object is used to create dates and time. It also offers methods to manipulate them.
The Function object allows you to define custom functions.
The Math object allows you to manipulate mathematical functions, such as trigonometric functions.
The Number object allows you to perform basic operations on numbers..
The RegExp object allows you to create regular expressions.
The String object provides a variety of methods for manipulating strings.