Soft zoning restricts only the fabric name service, to show only an allowed subset of devices. Therefore, when a server looks at the content of the fabric, it will only see the devices it is allowed to see.
Hard zoning restricts actual communication across a fabric. This requires efficient hardware implementation (frame filtering) in the fabric switches, but is much more secure.
Port zoning restricts specific switch ports from seeing unauthorized ports.
WWN zoning (also called name zoning) restricts access by a device's World Wide Name (WWN)