How does the UK postcode system work?

Related questions

1. How do I change my zip code to postal code?
2. Can two houses have the same postal code?
3. Is your postcode unique to your house?
4. Are all ZIP codes 5 digits?
5. What does my postcode mean?
6. What is postal address example?
7. What is a postcode district?
8. Why do postcodes change?
9. Can a postcode cover more than one street?
10. Can postcodes change?

Tags

1. #boxes
2. #deliverable
3. #grouped
4. #containing
5. #every
6. #master
7. #created
8. #royal
9. #normally
10. #points
11. #system
12. #delivery
13. #addresses
14. #postcode
15. #abbreviated
16. #maintains
17. #enable
18. #letter
19. #coding
20. #postcodes
21. #known
22. #database
23. #address