Difference between MEAN 2.0 and Angular Universal?

Question

Angular

Never worked with a server part. I recently learned about Angular Universal .
As I understand it, one of its cool features is that it makes NG2 applications "visible" to search engines.
Why not use MEAN 2.0 for these purposes ? We also use the server, you can also render the desired component for the request,
having previously worked out the content for search engines.
What is the difference? Or did I misunderstand the purpose?

Answer 1

Within MEAN, Express.js is only responsible for returning static to the client and processing API requests.
In AngularJS (the so-called first version), there is no way to run it at the time of processing a request from the browser directly to Express.js in order to form the HTML that AngularJS is responsible for and give it to the client.
Since this cannot be done, we sadly wave our handkerchief after the search bots.
Universal allows you to launch an Angular2 application at the time of processing an Express.js request, generate HTML on the server, give this HTML to the client, pick up the Angular2 application on the client and continue working from the state in which the application was after rendering on the server.