im new to javascript so please explain this code

// Week05: collections.js
// Script to demonstrate using the links collection.
function processLinks()
{
var linksList = document.links; // get the document's links
var contents = "<ul>";

// concatenate each link to contents
for ( var i = 0; i < linksList.length; ++i )
{
var currentLink = linksList[ i ];
contents += "<li><a href='" + currentLink.href + "'>" +
currentLink.innerHTML + "</li>";
} // end for

contents += "</ul>";
document.getElementById( "links" ).innerHTML = contents;
} // end function processLinks

window.addEventListener( "load", processLinks, false );