What is the difference between PCIe Gen 3 and PCIe Gen 4?

What is the difference between PCIe Gen 3 and PCIe Gen 4? m 2 ssd slot nvme pcie gen3 The ADATA LEGEND 960 PCIe SSD supports the latest Intel and AMD platforms and also meets the NVMe standard The LEGEND 960 supports PCIe and m2 pcie 40 in 30 slot QNAP QM2 series, 2 x PCIe 2280 SSD slots, PCIe Gen3 x 4 , 2 x Intel I225LM NBASE-T port Dimension : × × Weight

m2 pcie 40 in 30 slot 800 TB Note Speed may vary due to host hardware, software, usage, and storage capacity Some motherboards only provide PCIe x2 connections for the slot,

m2 vs nvme slot PCIE Gen3 X4: NVMe PCIe Gen3 x4 interface, PCIe and NVMe compatible, backward compatible, directly fits motherboards with slots using PCIE 2 through the PCIe slots What are the differences between , mSATA and NVMe SSDs? is commonly referred to as an mSATA