Think about what happens with the "old web". You make an HTTP request to a server. The server evals short snippets of dynamic language inside a template to gene

Think about what happens with the "old web". You make an HTTP request to a server. The server evals short snippets of dynamic language inside a template to generate a really big string. Then the server sends that string down the socket. If you want to view another object, you have to request another slightly different big string. Because of how resource-intensive it is to assemble these strings, programmers deployed "caching software" to memoize every big string that came up. Server hardware was loaded with RAM so that they could store a lot of big strings. - - - The new approach is to send the basic code of the website to the client the first time, then have the client make additional requests for data via AJAX, assembling the UI as it goes. Sanity.