What is the difference between ASI and SDI in Video?

In digital video broadcast (DVB), SDI is Serial Digital Interface an uncompressed form of A/V signal and ASI is Asynchronous Serial Interface an compressed form of A/V signal. The SDI signal hold the pids(audio, video, subtitle ...) of one channel, ASI can hold pids from multiple channels and in some cases (satelite uplink) some pids who describe the transponder(NIT, TID...)