Unsubscribing from Unique Mailing List vs "Contacts"

Unsubscribing from Unique Mailing List vs "Contacts"

If a lead/contact unsubscribes from a unique mailing list i.e. one that has been created by my organization and added leads/contacts to, are they only unsubscribed from that unique mailing list?

I wish to clarify this as important contacts and clients are receiving emails through the "Contacts" list, and therefore when they unsubscribe, we are no longer able to send them any emails at all.