Pages are more for static content, like your about page, contact, licensing, etc. Pages can have tags, which the search can pick up as well.
Posts, have the ability to be categorized as well as tagged, so you might have categories of breakfasts, dinners, deserts, etc. where you post recipes, for each of the categories, but a tag of eggs can apply to the full english breakfast post and the cake post in the dessert category. Posts, can even be a member of more than one category.
Pages don’t have categories, but can be organised in a hierarchical structure, one page the parent of another
Hope that helps.
