calling stations
A calling station is a weak player and a losing player. Important to always remember that when you are in doubt when faced with their calls.
They are indeed so-called passive players. Because they always call, but never bet or raise. Calling stations can be tough to play for new players and you will routinely here them complain that they never fold, that it is impossible to beat someone who never folds when bet into. On the contrary calling stations are some of easiest players to defeat when playing online poker. If you have difficulties, the recipe for success is extremely simple, never attempt a bluff against them.
In particular never try a double or triple barrel bluff with a calling station. Some of these players may fold frequently enough versus continuation bets. If they have some poker savvy they fold to a c-bet on a dry board, and you should run your c-bets almost normally against them. However,if they call, know that if you attempt a multi street bluff there is not a chance that they let their cards go. They may call all the way to the river with only bottom pair and still beat you.
On the other hand, the advantage of playing a calling station is that you can make thin value bets as they will often call such bets with a weak pair. So do not hesitate to make a value bet if you have top pair for 3 streets or even less
My recommended strategy to take money from these calling stations is to value bet systematically, almost never bluff, immediately fold when they display strong by betting, in particular in the unlikely event that they raise you, never ever slow play a calling station, but on the contrary 3-bet with the goods.
Hope this helps and good luck at the tables.