Onboarding is everything that happens between a user signing up and getting value from the product: setup steps, guidance, sample data, emails and help.
Good onboarding removes steps, explains only what's needed right now, and leads to one meaningful first result.
Welcome emails that nudge users who stalled can recover many of them.
Why it matters for a launch
Launch visitors are curious but impatient. Clear onboarding turns that curiosity into activated users.