What is the difference between adding {} and no braces after importing the module import Webpack

The Export default command is used to specify the defaults for the module output. Obviously, a module can have only one default output, so the Export Deault command can only be used once. Therefore, the import command does not need to append the parentheses, the other export output can have multiple, and import must be enlarged parentheses

That is, by import xxx from "..." introducing, xxx it is already the alias of the default export item.
Instead of importing the name of the item, it is the name of the import { xxx } from "..." { xxx } export.

What is the difference between adding {} and no braces after importing the module import Webpack