Hi Carolinett
Digital card making is where you create cards either:
a) Using your computer totally
You can download (alot for free) gorgeous 'pictures' of papers, embellishments, tags, ribbons, etc and use them in a graphics package (such as Paint Shop Pro) to design a card using your computer. You can also use a software package, such as Card Factory Deluxe to design everything.
You can then print off your cards, send them to somewhere like Vistaprint if you really want, send as an e-card - the green option ;) - as well as post your designs onto forums for ppl to see.
b) Printable Card Making Supplies (this is fab!)
This is where you don't design on screen, but instead print off the papers, tags etc. onto cardstock and use them as you normally would in papercrafting - this is instead of going out and buying them; download and print instantly.
Many people like to make their own papers and elements, for the challenge of creating realistic looking craft supplies :D
Its cheap, its instant (go get supplies NOW yummeeee) and its addictive!
Personally I like to do a mix of both - a bit of digi with printable stuff to embellish with.
I will find a good link for you to see some examples.
Sorry, long post - but it excites me 