I'm working on a little research project and noticed that sometimes these terms are not correctly used it may be confusing. It would appear that Wintersowing does provide both.

STRATIFICATION (the SEED): a brief cold-treatment (few days) of water soaked seeds to break seed dormancy, results in an even germination. It is unlikely that pre-chilling dry seeds will break dormancy.

VERNALIZATION (the SEEDLING): a longer cold-treatment (several weeks) of seedlings or young plants which promotes flowering. Osteospermum is one plant that will produce more flowers with vernalization

but what's a "cold treatment"? not freezing temps, right?

No, not freezing temps, just cooler growing temps. Different plants respond to lower temperatures at different stages of growth to initiate flower bud formation

well you helped me on the stratification too. i didn't know the seeds needed to be damp when you did that. thanks.