This is an advanced-use feature, and likely not something you'll need to configure. What you probably want is the content types reference

The text field represents a single line text input. It should be used for content values that are short strings: for example, a page title.

tinacms-text-field

Options

interface TextConfig extends FieldConfig {
  component: 'text'
  name: string
  label?: string
  description?: string
  placeholder?: string
}
OptionDescription
componentThe name of the plugin component. Always 'text'.
nameThe path to some value in the data being edited.
labelA human readable label for the field. Defaults to the name. (Optional)
descriptionDescription that expands on the purpose of the field or prompts a specific action. (Optional)
placeholderPlaceholder text to appear in the input when it empty. (Optional)

This interfaces only shows the keys unique to the text field.

Visit the Field Config docs for a complete list of options.

Example: Blog Post Title

Below is an example of how a text field could be used to edit the title of a blog post.

const BlogPostForm = {
  fields: [
    {
      component: 'text',
      name: 'title',
      label: 'Title',
      description: 'Enter the title of the post here',
      placeholder: '...',
    },
  ],
}