When I read Django code I often see in models what is called a "slug". I am not quite sure what this is, but I do know it has something to do with URLs. How and when is this slug-thing supposed to be used?
I have read its definition below in this glossary:
Slug
A short label for something, containing only letters, numbers, underscores or hyphens. They’re generally used in URLs. For example, in a typical blog entry URL:https://www.djangoproject.com/weblog/2008/apr/12/spring/ the last bit (spring) is the slug.