The following is a static import:

import module from "module-name";

It's statically resolved, before any code is executed.

This is a dynamic import:

const promise = import("module-name");

The reason why it's named promise is because import(...) returns a promise that resolves to the imported module (errors if module not found).

So you can use it like this:

import("my-mod").then((myMod) => {
    myMod.func();
});

Or the more preferred async/await syntax:

const myMod = await import("my-mod");

myMod.func();

Dynamic imports are executed and resolved at runtime which is why you must wait for it to complete. They're commonly used for code-splitting, lazy loading, or importing modules when needed (plugins could be an example).