If you only used one relay, your own relay, then your followers would need to add your relay to be able to see your events. Every relay that you write to on your profile has your events. It's good practice on have your own relay to backup your data in case the relays that you use goe down or the operators delete them in the future.
Discussion
Can you please explain the relay in an easy to understand language, cause until now I have been try to understand them but unfortunately, iam failing. What is the use of relay, please kindly note iam not tech savvy.
A relay is basically a server where notes (text only) are stored on. Instead of having one centralized server aka facebook, twitter etc. Nostr gives you the option to use multiple servers (relays) at the same time.
If one relay does not like your notes and decides to block/ban you, you can still happily use all the other relays.
Thank you very much, this really made it easy to understand 🙏🏽.