Gotcha, here goes. Labor creates value. Capital owners pay labor a fraction of the value they create then hold on to the surplus value which was created by labor that has already been completed. Capitalists then use that 'dead labor' to suck up more value from 'living labor' that they are currently extracting surplus value from. Similar to a vampire sucking blood from living creatures, using the power it already sucked from a creature it killed from sucking blood from.