Which browser introduced tab's option for the first time?

Firefox i think but not 100%

I'm also convinced that Firefox did

For this you will need to use server side programming to possess the users information and then a database to store it. Look on the internet for a PHP guestbook tutorial, that should give you a good basis to work from

Was it really firefox ?

I think tab's functionality is introduced by Mozilla Firefox first time.

seems it was around before then https://www.howtogeek.com/trivia/which-web-browser-was-the-first-to-feature-tabbed-browsing/

11 minutes ago, tk_hassan said:

I think Google Chrome introduce this feature for the first time.

Don't be daft. Tabs were around long before Chrome was  launched. Even IE had tabs before Chrome appeared.