Tank:
Description of WWI Technology
The usage of male and female tanks. Male tanks are armed with cannons, while female tanks make use of only machine guns. Most tanks (other than the US tanks introduced later in the war) did not have a fully rotatable turret, and instead relied on large amounts of weapons on board, whether it is machine guns or cannons. This led to a abnormally large tank crew, and coupled with thin armor (~6 - 10 mm thick) led to a higher chance of obtaining casualties. Vision from tanks were extremely limited to small slits, and relied heavily on frontal vision.
Description of WWII Technology
Most tanks have already incorporated some form of a fully rotated turret (excluding some types of Anti-tank Gun Carriages and Self Propelled Guns, which saw a small contribution to the war efforts). Female tanks were completely dropped unless incorporated into a anti-air gun platform, and instead relied on a main artillery and supporting machineguns. The US, for example, relied heavily firstly on 36mm main armament for their lend-lease tanks, and later replaced it with a 75mm and M1 Browning for supplementary machinegun on the M3 Lee and M4A1 Sherman. The Sherman later received an upgraded 76mm (American variant) and 17-pdr (British variant) later on in the war.
Airplane:
Description of WWI Technology
Planes saw very little fighting in the early stages of the war, and were usually unarmed and was used as surveillance of warzones. Many of the planes were made from canvas with a wooden frame, and so they could not sustain much added weight. However, later on they were typically armed with machineguns, and dogfights were introduced into the war. Planes also had the ability to hold small amounts of explosive ordinances to be dropped as bombs.
Description of WWII Technology
Planes were typically made of aluminum and, with stronger engines that had advanced throughout the years, allowed for stronger material to be used as well as allowed for more ordinances to be on the plane. The development of radar and night-vision systems (though premature) also allowed for night-time bombing raids and eventual dogfights to occur.
Infantry Weapons:
Description of WWI Technology
Infantry weapons were typically single-shot action rifles with limited semi-auto rifles, and they were paired with automatic machineguns. The machineguns are typically water cooled during this time, and had a slow cycling fire rate. Pistols were issued or brought for close quarter combat during this time.
Description of WWII Technology
Infantry weapons have become much more streamlined. Company equipment has been introduced, which typically allowed for a automatic rifle for the company leader, a machinegun with supporting semi-automatic rifles for the machine-gun platoon, semi-automatic rifles for the rifle platoon, and marksman rifles and semi-automatic rifles for the sharpshooter platoon. Bazookas were issued as well as flamethrowers throughout the war.
Weapons of Mass Destruction:
Description of WWI Technology
World War I saw to the large usage of poisonous gas, particularly mustard gas, phosgene gas, and chlorine gas, which caused a burning sensation on exposed parts of the body, and blisters inside the organs part of the respiratory system and a burning effect.
Description of WWII Technology
The most note-worthy WMD (and what characterizes WMD in today's world) is none other than the US's Uranium and Plutonium nuclear weapons, which were dropped on Hiroshima and Nagasaki respectively. The destruction led to the surrender of Japan, and a shock-and-awe to the rest of the world that catapulted the US to becoming a world leader as they were in control of WMD during the time. This will shift in a few years when the Soviet Union successfully tested their own WMD and both sides began to stockpile, resulting in the Cold War.
(See Comments for Strategic Tactic)