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

Most computers and storage drives still use the common SATA or PCIe interfaces to sling your bits of data around, but if you're lucky

1x SSD PCIe Gen 3x4 NVMe slot, $960 Dell XPS 13 9300 , 1x 1x 2280 NVMe Gen 3 slot + 1x 2280 Gen 4 ; 1x 2280 NVMe Gen

candy village slot BUT you go buy the off brand no name cheaper 1TB Gen 4 NVME for lets say, 70$ (6-7K read

cantik 77 slot Most computers and storage drives still use the common SATA or PCIe interfaces to sling your bits of data around, but if you're lucky