(1 minute 36 seconds)
(1 hour 23 minutes)
Take some time to watch these two videos; Banking on Bitcoin is a great documentary on the subject of cryptocurrencies.
Bitcoin will be the primary currency you use to trade for altcoins and store value until you're ready to cash them in for the currency of your choice. In trading, you will be "buying" altcoins with Bitcoin, and then later sell those altcoins for more Bitcoins than they were first worth.