They got a list of types of bluffs there. The article advocates not bluffing. But you should bluff against some players. Maybe look at your opponent's stats and what they do in certain situations to determine whether you should or not. Like if they fold to continuation bets a ton, take advantage of it.
Semibluffs are a type of bluff. Someone mentioned knowing when to use em. If you're playing against a guy who won't fold to the semibluff, make sure he'll call a larger bet in a later street that will make the money in the semibluff worthwhile if you do hit.
Cardchat has a strategy article about semibluffing:
Goes a bit more in detail about when to semi bluff.