javascript - Can get information (.get)

I try to fetch information from a public website area.
Let's just say I want the Product name and a Price of it only.
When I try to get the information from the site it giving me an error:

No 'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://demo.com' is therefore not allowed access.

The script I use is:

$(document).ready(function() {
    $.get("http://www.ebay.com", function(data) {
        console.log(data)

    });
});