When you're using information technology many people have now learnt that you do not have to type text that already exists. You can copy and paste it to wherever you want it.
Now with the internet you don't even have to do that. If something exists on an Internet web page, you can refer to it via it's link. Anyone can put a link into any document.
If you don't know how to do that or don't understand this ask me.
A benefit of putting up a link in say an email, as opposed to copying the text, is that it's easier to do so. Another benefit is that less information has to travel across the internet, which means it gets there faster and ther is less congestion. Especially if the link is to videos or photos.
One of the biggest benefits is that if the information linked to changes, those that read it, see the latest changes.