Perhaps you've seen some of FantasyWired's articles suggesting players to stream on your seasonal fantasy football team, but are unfamiliar with that strategy. In short, streaming is the strategy of plucking a player at a specific position (usually QB, DEF, K, or TE) off the waiver wire ahead of a favorable matchup the following week.
This is an effective way to make up for a deficiency at a position if you failed to draft an elite QB or TE, and is usually the best choice when looking for a kicker or defense. The NFL changes so much on a week-to-week basis, that it almost always makes more sense to look for players with favorable matchups that can produce the optimal amount of fantasy points.
Let's say you drafted a QB in the 11th round (Eli Manning), and are pumped about his Week 1 performance. He could also have a great performance in Week 2 against another lowly defense, but after that, his schedule becomes brutal for a few weeks. If that's the case, you can stash a lightly owned QB with a good matchup in Week 3, or target them on the waiver wire ahead of those games.
Drafting you fantasy team is less than half the battle, it's the management of your team, and the ability to pick up solid Kickers and Defenses on a week-to-week basis that will carry you into the playoffs.