What is an FCM token?

Related questions

1. What is push notification how it works?
2. What is topic in FCM?
3. What does push notifications mean on Instagram?
4. What service does WhatsApp use?
5. How does notification work in Android?
6. What is GCM service?
7. Is one signal really free?
8. Which is better GCM or FCM?
9. What is GCM encryption?
10. Does WhatsApp use GCM?

Tags

1. #startup
2. #messaging
3. #cloud
4. #groups
5. #generates
6. #initial
7. #token
8. #registration
9. #single
10. #devices
11. #registrationtoken
12. #create
13. #google
14. #commonly
15. #known
16. #client
17. #device
18. #instance
19. #access
20. #target