Being different, it will be separate from all other artifacts and outside of them. If the entity is defined by sameness then it will be plural, integral, similar in all things, and inside of them. In this case, we talk about balls as a group in which the most important artifacts are plural, the constituents of things, and the qualities of that groupness are the key. The entities like nouns are the basic artifacts, the building blocks of all others. Like nouns they can either be singular or plural - producing the two entity periods of knowledge.
Plural entities are inside, the same, common to all, and interacting.
To construct them we have to look at experience, to be realistic, to search within experience to find knowledge, to take the proper perspective and see the common elements. The distinction between artifacts in singular and plural periods is simply whether we construct entities based on difference or on sameness. Here we complete the logic of unique artifacts and find all of the forms of the elements of knowledge. When we look at all languages we again find a variety of common ways to specify such collections or categories. We distinguish common nouns, proper nouns, and mass nouns.