The difference between Hedgehog and Porcupine

Hedgehog as a noun:

A small mammal, of the family Erinaceidae or subfamily Erinaceinae (, the latter characterized by their spiny back and often by the habit of rolling up into a ball when attacked.)

Hedgehog as a noun (US):

Any of several spiny mammals, such as the porcupine, that are similar to the hedgehog.

Hedgehog as a noun:

A type of moveable military barricade made from crossed logs or steel bars, laced with barbed wire, used to damage or impede tanks and vehicles; Czech hedgehog.

Hedgehog as a noun (informal, military, historical):

A spigot mortar-type of depth charge weapon from World War II that simultaneously fires a number of explosives into the water to create a pattern of underwater explosions intended to attack submerged submarines.

Hedgehog as a noun (Australia):

A type of chocolate cake (or slice), somewhat similar to an American brownie.

Hedgehog as a noun:

A form of dredging machine.

Hedgehog as a noun:

Certain flowering plants with parts resembling a member of family Erinaceidae , the pods of which are armed with short spines. of South Africa.

Hedgehog as a noun:

A kind of electrical transformer with open magnetic circuit, the ends of the iron wire core being turned outward and presenting a bristling appearance.

Hedgehog as a noun:

A way of serving food at a party, consisting of a half melon or potato etc. with individual cocktail sticks of cheese and pineapple stuck into it.

Hedgehog as a verb (military):

To make use of a hedgehog barricade as a defensive maneuver.

Hedgehog as a verb:

To array with spiky projections like the quills of a hedgehog.

Hedgehog as a verb:

To curl up into a defensive ball.

Porcupine as a noun:

Any of several rodents of either of the taxonomic families Hystricidae (Old World porcupines) or Erethizontidae (New World porcupines), both from the infraorder Hystricognathi, noted for their sharp spines or quills, which are raised when the animal is attacked or surprised.