Web applications can be broken down into two core components: objects and classifications, or categories.
What’s an object?
An object is one of the main types of items, or things, involved in your application. Objects are sort of the “information building blocks”. Your application will ultimately be organized around the different types of objects involved. (Don’t worry, we’ll get into this in more detail later on in the course.)
For example, if your application idea was to create an application to store your favorite record albums and songs and share them with other people, your objects may be:
What are classifications / categories?
Whereas objects describe a certain kind/type of item, classifications, or categories, describe objects.
Going back to the example of the application for storing your favorite albums and songs, an example of a classification involved could be:
Classifications are very similar to objects, in that there are multiple different items for each type — such as pop, jazz, etc. for genres — but they are used more to provide additional information about the objects.
Objects vs. classifications
Here’s a good rule of thumb: objects can (usually) be easily translated to physical items in the real world; classifications cannot, they’re more descriptive and abstract.