Why is clustering called unsupervised learning?

Related questions

1. What is classification in DWDM?
2. What is a cluster Kubernetes?
3. What is cluster in was?
4. What is K inertia?
5. What is cluster technology?
6. What are clusters Crossfit?
7. What is a cluster Crossfit?
8. What is Hadoop master node?
9. What is the difference between regression and classification?
10. How clustering is different from classification?

Tags

1. #placed
2. #automatically
3. #group
4. #related
5. #might
6. #similar
7. #learning
8. #clusters
9. #divides
10. #unsupervised
11. #across
12. #items
13. #similarity
14. #clustering
15. #elements
16. #always
17. #machine
18. #groups
19. #definition
20. #basic
21. #applications
22. #together