sort function explained javascript

//sorts arrays of numbers
function myFunction() {
  points.sort(function(a, b){return a-b});
  document.getElementById("demo").innerHTML = points;
}var sortedArray = myArray.sort(function(a,b){
                                   if (a.name < b.name)
                                      return -1;
                                   else if (a.name == b.name)
                                      return 0;
                                   else
                                      return 1;
                               });