You know, eggs and sperm - that's how you make a baby.
The pollen essentially contains two sperm, one grows into a tube that propels the other sperm to the female egg through that little hole called the micropyle.
It's a bit confusing as you can have female pollen as well as make pollen. Male pollen XY, crossed with female pollen XX, and you have a 50% chance at males and 50% chance at females:
....X. Y
X|xx xy
X|xx xy
When you stress a female plant to produce pollen it's XX pollen crossed with an XX egg which produces XX female seeds:
....X. X
X|xx xx
X|xx xx
The ovule is located in the ovary which is located in each calyx.