The /ask page lists text posts, i.e. those which include a text body rather than a link (what reddit calls "self-posts"). It's named "ask" because "Ask HN" post

The /ask page lists text posts, i.e. those which include a text body rather than a link (what reddit calls "self-posts"). It's named "ask" because "Ask HN" posts are one of the more common kinds of text posts, but it treats all text posts the same.