This works only with the Straight Talk Hotspot and you first have to purchase the hotspot in order to use the service card featured on this page.
Here is the link for the page to see and order the hotspot ...it is currently selling for $79 at Walmart (copy-and-paste):
What the hotspot essentially does is to create a wifi signal for you to use with your chosen device whether it be your smartphone, tablet, laptop, desktop, iPad, etc. ...anything that can use wifi. You can have up to five devices connected at once. It's your own personal wifi signal and sometimes called MIFI so you can have internet access with you instead of relying on public or private wifi. This way, you don't have to use the wifi at the hotel, or Starbucks, or the airport, etc., etc.
It works independently from your personal cell phone but DOES use a cellular connection (Verizon Wireless --so you have to be in an area of Verizon cell coverage for this to function).