User onboarding is the self-serve onboarding experience in which a visitor who signs up for a product creates an account and becomes a user.
What is user onboarding usually associated with a free trial or freemium customer acquisition strategy or pricing model
It's a self-serve onboarding experience that happens when a visitor signs up for a product, creates an account and becomes a user and then goes through a signup flow and the first experience of that product into hopefully experiencing the promise of that product before deciding to upgrade and becoming a customer or churning.