slice(from, to) - shallow copy of a range defined by its end points.

splice(from, length) - shallow copy of a range defined by the number of elements in it

examples/arrays/slice.js
"use strict";

var names = ['Foo', 'Bar', 'Morse', 'Luke', 'Lea', 'Han Solo'];

console.log(names.slice(3, 5));   // [ 'Luke', 'Lea']
console.log(names.splice(2, 3));  // ['Morse', 'Luke', 'Lea']