It's a kissing cousin to the
bluff. The difference is that the bluff bet happens when you have nothing, but the info bet/raise comes when you have something but maybe not enough.
The info bet should be used sparingly. For one, you really shouldn't be playing that K5, so you really shouldn't need to find out if, when the K flops, yours has a chance.
The info bet is best used on the flop, when the minimum bet is smaller. It's a lot trickier in NL, and can get you in serious trouble.
I'm not that advanced a player, but I do like utilizing this question-bet occasionally -- especially when the pot is big but the risk is greater.
The most important part, when posing this bet that is a question, is
listen to the answer.