Imperative vs Declarative

Imperative:

It is a code that says the machine, what to do and how to do.

Ex:
for (let i = 0; i < 1000; i++) {
    console.log(i);
}

Declarative:

It is a code that says the machine, what to do and what should happen. It doesn't tell how to do. Ex: Humans

Ex:
[1, 2, 3].forEach(item => console.log(item));

Functional programming is mostly be a declarative, we don't say how to do.