What is union of Arrays?

Union of arrays would represent a new array combining all elements of the input arrays, without repetition of elements.

let arrOne = [10,15,22,80];
let arrTwo = [5,10,11,22,70,90];

// Union of Arrays
let arrUnion = [...new Set([...arrOne, ...arrTwo])];
console.log(arrUnion);

What is intersection of Arrays?

The intersection of two arrays is a list of distinct numbers which are present in both the arrays. The numbers in the intersection can be in any order.

let arrOne = [10,15,22,80];
let arrTwo = [5,10,11,22,70,90];

// Intersection of Arrays
let arrIntersection = arrOne.filter((v) =>{
    return arrTwo.includes(v);
});
console.log(arrIntersection);

Demo -