PCMark7 uses traces based on modern software from the Windows 7 era. This benchmark is the most important one when deciding which SSD to buy, since it uses actual and current applications. A difference with PCMark Vantage is that PCMark7 runs the traces in real-time. Because of this the SSD scores are closer to each other, but the results also correlate better with what you can expect in real-life.
The Windows Defender test is based on a trace in which Windows Defender performs a quick scan of the system.
The importing pictures test is based on a trace in which 68 photos from a USB stick are imported into Windows Live Photo Gallery. The pictures, which have a total size of 434MB, are copied, indexed, and turned into thumbnails.
The video editing test is based on a trace in which an HD video is exported from Windows Live Movie Maker. The film is based on previously imported 1080i MPEG2 videos from a Sony HDR-HC3 camera.