Buffering elements into containers such as List, the result stream has the Flux>type.

Windowing elements into a stream of streams such as Flux>. Note that, now, the stream signals not values but sub-streams, which we can process.

Grouping elements by some key into a stream that has the type Flux>. Each new key triggers a new GroupedFlux instance and all elements with that key are pushed through that instance of the GroupFlux class.

Buffering and windowing may happen based on the following:

The number of processed elements; let's say every 10 elements

Some time-span; let's say every 5 minutes

Based on some predicate; let's say cutting before each new even number

Based on an event arrival from some other Flux, which controls the execution