There are four (4) sides of a ship. The Bow is the front of a ship. The bow has about 50% (1/2) of your default broadside armor integrity. While the bow is about twice (2x) more resilient than the Stern, it's still a vulnerable part of your ship.
Since the default value of the bow is higher than that of the Stern, it could be useful to take Fittings to increase that value, especially if your thinking about Charging.
For more information: Hull.
This information is provided by the update that PotBS Wikia is undergoing, by Captain Vuur.