What are the purposes of prism-live-xxx.js

[cyfung1031]

In the base prism, the languages are already included. (prism-css, prism-javascript, prism-markup)
The syntax are displayed correctly.

Even the following three .js files are not loaded, every things work fine.
So what are the purposes of prism-live-xxx.js??

prism-live-css.js
prism-live-javascript.js
prism-live-markup.js

[LeaVerou]

Snippets, what do things like Cmd + / do, autocompletion, things like that.