Vue.js: What is Pinia in Vue?

1// stores/counter.ts
2import { defineStore } from "pinia"
3
4export const useCounterStore = defineStore("counter", {
5    state: () => ({ count: 0 }),
6    getters: {
7        doubleCount: (state) => state.count * 2
8    },
9    actions: {
10        increment() {
11            this.count++
12        }
13    }
14})