I am quite unfamiliar with server hardware so please cut me some slack.

I am a network administrator and hosted services provider (webhost, voip, etc) to small businesses and I have a couple of servers that have pcie slots labeled PCIeX8 and PCIeX4. Are these just normal run of the mill pcie slots that are x4 or x8 instead of the standard x16? Are there any video cards that would get a decent hashrate and work in these cards?

Thanks for your help.