A pipeline means doing an operation in little bits, each in 1 clock time - at the cost of extra latency - so a slow combinatorial function might be split into 3

A pipeline means doing an operation in little bits, each in 1 clock time - at the cost of extra latency - so a slow combinatorial function might be split into 3 pipe stages each doing 1/3 of the function with data arriving 3 clocks later Metastability is what can happen if you change data at the instant (or close to the instant) that a synchronous flip-flop is clocked - the resulting value that's stored is neither a 1 or a 0 but instead the storage element ends up oscillating at a high frequency - this little bit of evil can infect subsequent logic stages resulting in a chip that's a horrible hot buzzy mess of crud