The difference between howitzer and cannon is mainly in function, which can also be seen through appearance.
A cannon is a large-caliber gun classified as a type of artillery and usually launches a projectile using explosive chemical propellant. While a howitzer has a thick barrel and generally a large ranged weapon between an artillery gun which has smaller, higher-velocity shells fired at flatter trajectories.
The term “Cannon” appeared around 1670, when it was defined as “a cannon that can be fired from a carriage or a fixed support, with a barrel larger than one inch”. Later, the cannon was specifically referred to as a direct-fire artillery with a length-to-diameter ratio and used for flat ballistic attacks, and it has been used until modern times.

Because the barrel is relatively long, the cannon can provide a longer acceleration distance for the projectile and make fuller use of the launch energy. Therefore, the projectile fired by the cannon has huge kinetic energy and a very fast flight speed.
This results in the flat trajectory of the cannon, so cannons are generally not used to attack targets outside the visual range. They are the most important heavy direct fire on the battlefield.
For example, naval guns, anti-tank guns, tank guns, and machine guns of warships all belong to the category of cannons. Even those multi-barreled Gatling are cannons.
The barrel of the Howitzer is shorter than that of the cannon, and some models have lower pressure resistance. They mainly attack the target in the form of indirect firing, and the ballistic curvature is also longer.

In actual use, howitzers usually form units in the form of artillery groups, covering, blocking, and extending the enemy’s various artillery tactics. They are one of the most important killing forces on the battlefield.
Because of the larger curvature of the trajectory and the slower flight speed of the projectiles, howitzers are more difficult to shoot directly at the target like a cannon, but it is more suitable for larger-caliber projectiles.
For example, in the past there was a tactic. The artillery first covered, then partly extended shooting, and part blocked the shooting. Infantrymen stepped on the cannon bomb point to continuously follow up and charge, which was very cruel. cannon cannot be used in This tactic.

This is also the reason why most field guns are howitzers, while tank guns are all cannons (there were also infantry tanks with howitzers in World War II, such as the M4 105mm Howitzer in the picture above). The infantry needs the cannon to provide direct firepower to quickly solve the target in front of it, but it also needs the howitzer group to carry out large-scale damage to the enemy, or even annihilate it.
Therefore, whether it is a cannon or a howitzer, or a combination of the two, there is only a division of labor, and the power cannot be divided easily. Moreover, the type of ammunition used has a great influence on the power performance of the two artillery in different scenarios.

For example, when hitting tanks, the shelling-piercing shells fired by the cannon and the high-explosive shells of the howitzer are two different things. Penetration relies on the high-kinetic energy core to drill through the tank, and fragments, jets, and high-temperature effects enter the interior to kill.
High-explosive grenades can only explode in the outer shell, causing a certain impact damage (even flying); before the caliber reaches a certain level, the damage to the front armor of the tank is extremely limited, let alone killing the internal occupants.

But if it is to blow up houses and kill people, the destructive power of high-explosive ammunition will only be unmatched. They can easily create a huge range of coverage kills. One-shot can make the house go up to the sky, and the fragments will kill dozens of them.
Of course, the cannon can also be used for the grenade, which is mostly used for clearing obstacles and killing personnel. Modern artillery combines the cannon and howitzer to create a howitzer, which combines the performance of the two and can adjust the charge to achieve different firing angle requirements. Modern artillery are almost always equipped with howitzers.