Saving means easier access to spending it. But when you invest it chances of earning more out of it and holding it for some time before you can spend it
well, when you invest chance of earning more increase, but don't forget equal chance of loosing will also came along with chance of earning.
when you invest you can face either profit or lost.
Saving is for short term things, while investing is really good for long term. when you invest chances of loosing your money is quiet low, while when you do trading you might loose all your money. well in terms of investing the higher the risk, the higher the income.