JavaScript is a high-level, dynamic and interpreted programming language that is well-suited to object oriented and functional programming.
JavaScript was created at Netscape in the early days of web, and they wanted to standardize the language. So, Netscape submitted the language to European Computer Manufacturer’s Association (ECMA) for standardization. But, there were trademark issues with the name JavaScript, and the standard became called ECMAScript.
The core features of JavaScript are based on the ECMAScript standard, but JavaScript also has other additional features that are not in the ECMA specifications/standard (Ex. DOM). JavaScript mostly implements the ECMAScript specifications. ActionScript and JScript are other languages that implement based on the ECMAScript (ES).
It is a prototype-based programming (style of OOP), in which the existing objects are cloned/reused without creating any parent class. Objects inherit from object.
//First Object
var objOne = {title: "Object One", first: 1, second: 2 };
//Second Object
var objTwo = {first: "first", third: 3}
//objOne is now prototype of objTwo
object.setPrototypeOf(objTwo, objOne);
objTwo.title //Object One
ObjTwo.third //3