What does short form mean by hash abbreviation?

Question

Vue.js

I came across a code that I managed to get to work, but I don’t understand how it works:

{{ item.created_time | date }}
{{ item.closed_time | date}}

What does the #item.{lalala} abbreviation mean ?
What's the point?
The whole day kneaded the official Vue docks, nothing could be found.
Gull interprets the word "hash" in his own way, and gives the results off topic.
Project: Vue + Webpack + TS + Vietify etc.

Answer 1

angle brackets are collected by the editor

There is a special button to insert the code.
Now for the question. This is the new syntax for the slot name.