Angular Universal

Angular Universal is a concept which enables server side rendering (SSR) of Angular applications. By default Angular applications are executed in the browser and rendered to the user. With server side rendering the Angular application is compiled into HTML in the server side and sent to the browser as HTML this enables quick rendering of the page in the browser.

Usually the server side rendering is used to render the first page of a website so that the user does not have to wait long once he hits the URL in the browser. Once the first page is rendered to the user, the Angular application gets downloaded to the browser and the subsequent requests will be server by processing the Angular application. Without server side rendering the user has to wait for the Application to be downloaded and processed in the client side before he sees the first page.

Server Side Rendering in React v16.0

React 16 improves the speed of server side rendering. React 16 provides a new hydrate() method to render components which are processed in the server side.

Server side rendering is performed with Node web servers express, using the renderToString() method which compiles the react component in the server side and send the HTML to the client.  

What's new in React 16.0

React v16.0 comes with major changes in the underlying architecture, with limited changes to the pubic API so the way we write react code doesn't change much, but the internals have changed drastically.

Some of the key new features introduces in React 16 are fragments, error boundaries, portals, improvements to server side rendering and reduced library file size.