Data that is passed around in Vapor is often derived from the Content type. It's a class that conforms to Codable, which means that it can convert from and into JSON, XML, or any other data structure without any issues. Take a look at the following struct:

struct SomeData: Content {
    var stringValue: String
    var optionalValue: String?
    var anotherValue: Int
    var anotherContent: ClassThatIsContent
}

In JSON, the data could look like this:

{
    "stringValue": "a random string",
    "anotherValue": 10,
    "anotherContent": { ... }
}

We can use any object or class that is implementing the Codable protocol. All the standard types (String, Int, and Bool) are conformed by default. But we can also implement our own types. This allows us to represent even complex JSON structures easily by building all the needed structs (or classes).

Content is a helpful protocol that allows you to write structs or classes for your inputs and outputs.