What are the differences between PCR and qPCR?

PCR is qualitative, while qPCR is quantitative. if no detection method (e.g. gel electrophoresis) is done for PCR, there is no visual output. in qPCR, a fluorphore is added to the sample and the reaction is carried out in a thermal cycler which illuminates the sample with a light beam of a specific wavelength. in qPCR, the sequence copy number can be detected in real time.