It could also mean that the housing draining system connected to the dishwasher has a problem and that could be blocked up. If you cannot find the problem yourself or do not feel confident enough in your DIY skills to fiddle with the dishwasher, call a plumber out as soon as possible to have a look at the problem.
The problem could also be down to an air vent that has not been installed properly or that has since become loose due to repeated use. Then again, if you have had the dishwasher for quite a few years, the problem may need to be resolved by getting a new drainage valve or hose. Your plumber should be able to advise you on what the best course of action is for you to take, depending on what is actually wrong with your dishwasher.
Alternatively, you may be able to consult the dishwasher manual and figure out the problem by having a look at it yourself.
Of course, it goes without saying that you should put off washing any dishes until you get the problem sorted, as nobody likes having dirty water all over their kitchen floor.