NOSTR is a protocol just as POP3, IMAP and SMTP are protocols for e-mail. Everyone can have their own e-mail but everyone can write to anyone else who has an e-mail application.
Same with NOSTR, you can use it for various services:
social networking
video streaming
chat
community
etc. etc... With the key difference being that you don't need to make an account for each service and you won't have to build up a following of contacts, but you will find everything in each NOSTR-based service. Nostr also has many other advantages, but you are a 5-year old child and it is already a lot if you have managed to understand everything I have written above :)
NOSTR is a protocol just as POP3, IMAP and SMTP are protocols for e-mail.
Everyone can have their own e-mail but everyone can write to anyone else who has an e-mail application.
Same with NOSTR, you can use it for various services:
With the key difference being that you don't need to make an account for each service and you won't have to build up a following of contacts, but you will find everything in each NOSTR-based service.
Nostr also has many other advantages, but you are a 5-year old child and it is already a lot if you have managed to understand everything I have written above :)