Sanitation is the effective use of tools and actions that keep our environment healthy. These include latrines or toilets to manage waste, food preparation, washing stations, effective drainage and other such mechanisms.
Hygiene is a set of personal practices that contribute to good health. It includes things like hand-washing, bathing and cutting hair/nails. Hand-washing is the single most important activity we can all do to encourage the stop of disease.
The difference is subtle but important. While both sanitation and hygiene are related, we must be taught both effective tools and effective behaviors to protect our health. Imagine how important these can be in places without a toilet or where hand washing has never been learned!