Sperm would refer to the microscopic organism that can usually be found in semen. The sperm is known to be very small, but it has the ability to swim to the ovaries of the female and fertilize the egg. Do remember that there is usually a lot of sperm that can be found in a small sample of semen, so it does not matter how much semen is available, it would still contain a lot of sperm.
Most of the sperm cells die before they reach the ovary, but there are instances when some are able to fertilize the egg. The semen does not have any other characteristics aside from the fact that it can keep the sperm more motile.