To allow JSON tag names to NOT match field names, setters, and getters.

Ex:
Where a JSON object contains a tag like this: "name": "John",

It would properly populate a field in a class like this:

@JsonProperty("name")
protected String mPrettyName;

public String getPrettyName() {
    return mPrettyName;
}

public void setPrettyName(String prettyName) {
    mPrettyName = prettyName;
}

Note that the field, setter ,and getter do NOT match the JSON tag name.