What is a Sata Express

[Slidemission]

I own a z170 A Asus motherboard

What is a Sata express?
Why should I use it?
Pros and Cons?
Should I connect my ssd and HDD to the Sata express together?

 

[MeanMachine41]

SATA Express (abbreviated from Serial ATA Express and sometimes unofficially shortened to SATAe) is a computer bus interface that supports both Serial ATA (SATA) and PCI Express (PCIe) storage devices.
Go here: https://en.wikipedia.org/wiki/SATA_Express
Describes fully the advantages. No cons and is backward compatible.
The SATA III specification allowed for up to 6Gbps (600MB/s), which was fast back in the day, but now with the new the SATA Express standard you can expect speeds of up to 16Gbps (1.97GB/s)