Instances are how we create individual objects using a structure. In the previous exercise’s example, we created a structure to model dogs:

struct Dog {
  var age = 0
  var isGood = true
}

In Dog, we’ve modeled some general traits dogs have. However, each dog is unique in their own way — to represent this programmatically, we have to create different instances of dogs!

var eloise = Dog()

In the example above we’ve created a single instance of the Dog struct by adding parentheses () to Dog and save it to the eloise variable.