The structure on the right is saturated while the structure on the left is unsaturated (presence of double bond). At room temperature the saturated fat will be solid and the unsaturated fat will be liquid.
High consumption levels of saturated fats are associated with heart problems. Consumption of high levels of saturated fats can raise your cholesterol levels and increase risk of heart disease.
Unsaturated fats are not associated with heart problems.
An example of saturated fat would be the fat found on red meat. An example of unsaturated fat would be the fat found in nuts, avocados, etc.