诸位 (zhū wèi) is a very formal, respectful way to say 'everyone' when addressing a group, often used in speeches or written announcements. It is more formal than 各位 (gè wèi) and much more formal than the everyday 大家 (dà jiā). 大伙儿 (dà huǒr) is colloquial, while 众人 (zhòng rén) is literary.