Intro component signup form (HTML + SASS + JS)

Hello everyone, This is my solution for this challenge.

I would say, this was my first time using sass, I'm not sure if im organizing my sass correctly. I learned a lot about forms and validation from this challenge. I don't have much experience with forms and im still learning java-Script.

One thing that i don't understand is the code i copied, it checks if the email format is correct or not.

function isEmailValid(email){
    return/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email);
}

I understand the java script part of it but, I don't understand that line of random characters. I know what's it doing but i don't understand how its doing it. So like am i really supposed to know this or can i just copy it every-time? Let me know if there's anything i can improve on.

Thanks!