Content Types are simply structure for your content. Each type defines what fields to be used and what order they should be displayed. Currently you can create 25 content types per app, although this is subject to change in the future.
Adding a new content type is virtually the same as adding a new app. The only difference is along with naming it, you also have to declare an API ID. By default, the API ID will be auto-generated based on the name, but can be manually altered prior to submitting. You cannot alter the slug after the content type is created.
Clicking the Pencil icon on a type will direct you to the page to modify it. Next to the pencil icon will also be a plus(+) symbol and clicking it will create a new piece of content of that type.
At the top of the editing page, you can modify the name. The slug isn't editable.
The delete button can be found on the bottom right of the page, but all content of that type must be deleted prior to deleting the type.
Adding a new field is similar to creating a new content type. You must provide a name and a slug, but you also select the type of field.
Reordering fields can be done by dragging the handle (two lines) on the left side of any field. Changing the name and slug for the field can be done on the edit modal revealed by clicking the ellipsis(...) on the right side of the field item. Keep in mind that you'll also need to change the slug to match in your website or app. To make a Short Text field unique, open that same modal and check the Unique box.
To set values for a Dropdown, click Edit Values in the field editing modal. Values must be 80 characters or fewer. The values can be dragged to be reordered for future selection order. When you're finished, remember to click Save or new values will be discarded.
The Title field is used on the Content tab to help you identify items. If there is no title field, all content of that type will be untitled. The first Short Text field created in a content type will be auto designated as the title field. To designate a different field as the title, open the desired field's settings and check Content Title.