An injection mold can contain one or more cavities.
The number of cavities is often named cavity count.
In general it is considered that all the cavities are identical if we talk about cavity count.
The more cavities in one mold, the more parts can be produced at once.
Therefore production time and part costs can be reduced.
The disadvantage is that in the event of a mold failure, the number of missing parts increase fast in a short time.
The higher the cavity count, the higher the required clamping force and thus the size of the injection molding machine.
A complex part requires a complex mold, therefore a lower cavity count is more likely.