what is a park? what is a theme park? a park is a public area of land with grass, trees, etc, where people can walk for fun or children can play. a theme park is a large area which is designed around one subject such as water, food, culture, science or history. the difference between a park and a theme park: the general purpose of a park is for people to walk in for pleasure or for children to play in it. a theme park is fun to visit, but it can also be educational and can offer useful information.