qPCR is short for quantitative Polymerase Chain Reaction and is also known as real-time polymerase chain reaction (real-time PCR). It is a laboratory technique that monitors the amplification of a targeted DNA molecule during the PCR (i.e., in real time) and thereby not at its end as in conventional PCR.
Real-time PCR can be used quantitatively (quantitative real-time PCR) and semi-quantitatively (i.e., above/below a certain amount of DNA molecules) (semi-quantitative real-time PCR).