An action is a payload of information that sends data to the store. Using these actions is the only way components can request or send data to the Redux store, which serves as the global state object for the entire app. An action is just a plain JavaScript object. We'll be defining functions that return these actions. A function that returns an action is called an action creator.
In this recipe, we'll create the actions to load the initial images for the gallery. During this recipe, we'll be adding hardcoded data, but later on, we'll request this data from an API to create a more realistic scenario.
