How do browser extensions work?

Related questions

1. Does uBlock origin work incognito mode?
2. Does Firefox have free VPN?
3. What add extension means?
4. Are browser extensions safe?
5. What is Browsec extension?
6. Does incognito mode actually work?
7. Does Adblock record browsing history?
8. Is chromium a virus?
9. Is private browsing safe?
10. Does incognito actually do anything?

Tags

1. #enable
2. #tailor
3. #small
4. #experience
5. #technologies
6. #functionality
7. #users
8. #extensions
9. #preferences
10. #customize
11. #browsing
12. #built
13. #javascript
14. #software
15. #behavior
16. #individual
17. #chrome
18. #needs
19. #programs