It is recommended for web developers to understand this language and get good command over it.For using core JS you don’t need any libraries just put your code inside script tag. See Example Below
Less server interaction − You can validate user input before sending the page off to the server. This saves server traffic, which means less load on your server.
Immediate feedback to the visitors − They don’t have to wait for a page reload to see if there is an error in the form input.
Increased interactivity− You can create interfaces that react when the user hovers over them with a mouse or activates them via click event.
Richer interfaces − JS gives a nice interface to users by allowing you to add sliders, drag and drop, tabs, validation etc.
It lacks in multithreading or multiprocessor capabilities
It has security issues
Frameworks describes a given structure of “how” you should present your code. Pretty much like a code-template.
Libraries are like toolkit that aid you in various tasks
Frameworks and Libraries…
1)Angular Js – AngularJs is a google product and one of the most used java script based framework. It was released in 2009 and it is open source. AngularJS is a structural framework for dynamic web apps. It lets you use HTML as your template language and lets you extend HTML’s syntax to express your application’s components clearly and succinctly. AngularJs helps eliminate much of the code using its data binding and dependency. All the process is done within the browser which makes it faster and works better with server technology.
2)Meteor Js – Meteor Js is open source Js Framework written in node js, it requires jQuery library or Js UI library to run. Meteor allows for rapid prototyping and produces cross-platform (Android, IOS, Web) code
7)jQuery – It is a library which offers good features which makes java script rich. It makes HTML page more rich and user-friendly with event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers.
10)Ionic Js – Build mobile apps with the web tech you know. It is an open source,Cross Platform.