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
