Refers to the person or entity that plans and runs an event, conference, or competition. Can imply both organizational and financial backing.
大会の主催者は地元の企業です。
The organizer of the tournament is a local company.
主催者側の都合でイベントが中止になった。
The event was canceled due to circumstances on the organizer's side.
プロモーター often implies a professional organizer of commercial events like concerts or boxing matches, while 主催者 is the general term for whoever hosts or organizes any event.
主催者 is the person or group who hosts and runs an event, while 発起人 is specifically the one who first proposed and pushed the idea forward.
主催者 is the host or sponsor who officially puts on an event, while 幹事 is the person who handles the practical planning and coordination, often on someone else's behalf.
主催者 is the organizer who runs the event, the opposite role to 参加者, the person who joins it.
主催者 is the host or organizer of an event, the role opposite to 来賓, the invited guest attending it.
Compound of 主催 (shusai, 'sponsorship, organization') + 者 (sha, 'person').