ajax: AJAX stands for "Asynchronous JavaScript and XML" (Asynchronous Javascript and XML), it is a web application for creating interactive web development technologies.
advantage:
1, no page refresh, the user experience is good
2, asynchronous operation, fast response
3, on-demand data requests, bandwidth and reduce the burden on the server
4, based on standardized technology, do not need to download plug-ins and applets
Disadvantages:
1, does not support the Back button
2, security issues, ajax exposed the details of the interaction with the server
3, is not conducive to seo
JSON: the JavaScript Object Notation acronym, which is a data exchange format.
advantage:
1, lightweight, small bandwidth
2, easy to read and write
3, support for multiple languages
Disadvantages:
1, read by eval (), es6 canceled eval (), eval () with a certain risk
2, no XML format promoted so widely