Oh, no problem. A starter is basically making a mini beer first. There a a lot of threads here just do a quick search. Any way the jist of it is you add some DME to boiled water, cool it down and pitch the yeast into it. For 5 gallons a 1 liter starter is normal. After 2 days you pitch that into your wort. The benefits are huge. First you make sure your yeast are healthy before you put it into your precious wort. Second you grow more yeast making sure you have plenty to pitch (1 packet isn't enough usually, although you can still make good beer without a starter so don't worry)
Look it up, I am just bieng general here. You won't regret it.