Intuitionism is an approach in moral philosophy which says that human beings have an intuitive moral sense that enables them to detect real moral truth. Intuitionists think that good and bad are real objective properties that cannot be broken down into component parts.
Something is good because it is good; and its goodness does not need justification or proving. Intuitionism does not mean that all moral decisions are reached relying solely on basis of intuition.
Intuitions help in discovery of basic moral truths, then decision-making and making moral judgements occur in ordinary sort of way.