[javascript] Javascript ES6 export const vs export let

Let's say I have a variable that I want to export. What's the difference between

export const a = 1;

vs

export let a = 1;

I understand the difference between const and let, but when you export them, what are the differences?

I think that once you've imported it, the behaviour is the same (in the place your variable will be used outside source file).

The only difference would be if you try to reassign it before the end of this very file.