Technically, a nightclub is just a venue. What happens at that venue is one or more nightclub events. As per the definition of a nightclub, those events are characterised as:
- They occur at night
- They have drinks served
- They have music
- They have a dancefloor.
See the nightclub article for more details.
Most nightclubs will have a number of different events happening on different nights of the week. They will generally be very similar in how the club is laid out during the events, but not always. Some of the events may have different age ranges (e.g. so-called "student nights").