Spread operator (…) : spread operator (...)
sspread operator is used to spread or expend an array,
Ex:
se1= [1,2,3,4];
set2 =[...set1,5,6,7,8,9]
output : [1,2,3,4,5,6,7,8,9];

Example : set1 ={
name : "abc",
email: "abc@gmail.com"
}
set2 ={
...set1,
age:20
}
console.log(set2)


Rest operator :
ES6 brought rest parameter to ease the work of developers.
For arguments objects, rest parameters are indicated by three dots … and precedes a parameter. With this, set indefinite number of arguments as an array, which is Array instances.
Example :

(html>
(body>
(script>
function addition(…numbers) {
var res = 0;
numbers.forEach(function (number) {
res += number;
});
return res;
}
document.write(addition(3));
document.write(addition(5,6,7,8,9));
(/script>
(/body>
(/html>