Seminars are usually shorter events, lasting a couple hours, ½ day, or a even a whole workday. They have single or multiple speakers, and generally keep all participants together in the same space. Conferences, on the other hand, typically have multiple sessions that occur concurrently that are geared toward different interests, different positions or roles, and even skill level. They are typically held at hotels, begin with a keynote session and then hold breakout sessions by topic. A conference is usually planned for at least half of a day though generally conferences span the course of one to two days or sometimes longer.