Short pipeline or long pipeline
If by pieces one means possible stages that the instruction can be split into. For example, like this "short" Classic RISC pipeline with five stages:


Fetch Instruction Stage: Fetch the instruction.
Decode Instruction Stage: Decode the instruction.
Execute Stage: Execute the instruction.
Memory Access Stage: Access (read/write from/to) the memory.
Writeback Stage: Write results to the CPU registers.


Then a short pipeline means that the instruction is split into a low amount of these stages (pieces), but the amount of hardware and time spent in each stage will actually increase (length of the pieces) compared to if there were more stages.