Somebody asked me this question recently. Let me attempt it. Am not sure Grandma can understand it but Atleast your dad will.
Have you heard of Live telecast of Cricket match or Live telecast of Miss India competition on your TV? If you watch an event live / real time sitting at your home, on your TV, it is called live telecast and if you watch the same on Computer or mobile phone it is called as live streaming.
However, the underlying technology is completely different. Let me illustrate it.
As you can see the primary difference is the internet because for live streaming you require a high-speed internet connection. You can watch live streaming event through Portable devices live streaming , so ZifiLink provides you high speed internet connection anywhere and through ZifiLink internet bonding router even while you are travelling or your in the remote place you can access high speed internet because now you have the freedom to watch your favourite match while taking a walk in the park. However, live telecast provides you the highest quality video at cheaper rates.
Another primary difference is while live telecast is regional, live streaming is global. For example, While you can watch a cricket match on Sony Max in India, it is unlikely that you can watch the same from Sudan. However live streaming event you can watch from anywhere in the world where internet connection is available*
* – Though internet censorship can block certain contents, I intentionally skipped it to keep the article meaningful for your Grandma.