Cancer begins from various cells that are important for life. What happens when a normal cell turn to cancer cells? This information is important to understand about cancer. Our body is made up of different types of cells. To keep body healthy, cells are to be produced regularly. Whenever a cell get stale or dies, then another cell take place of it. Sometimes this procedure goes wrong. Cell's wrong DNA starts giving birth to mutation which affects cell development and division. On this occurrence, the cell which should be dead does not dies and the cells which were not to be produced starts producing. And this huge amount of cells are known as tumour.