Health is a general term used to describe a complete state of wellness in a number of possible areas such as physical, mental, spiritual, emotional and social well-being. Health can also be used to mean the absence of disease, illness or injury.
Fitness is one aspect of physical health and is made up of attributes such as strength, flexibility and endurance.
The two terms are loosely related in that good physical health can often lead to good fitness. However this in not always the case. For example a fit individual may have physical health issues through lack of sleep, stress or substance use.