Answer: Technology : Tank had been designed in such a manner that it provided attack (fire), protection and movement facility at the same time. It was armored vehicle designed with advanced technology prevailing at that time. It had internal combustion engine with armor plating.
Usefulness in World War I : Tank carried a crew of army from one place to another at a faster pace. It could hit the target at long range also.
It was highly unreliable but still ended fear of trench warfare and brought back some mobility to Western Front.
Tank helped to overcome obstacles and barbed wire.
Step-by-step explanation:
Tank was first used by Britishers on 15 September 1916 in the Battle of Flers-Courcelette.
Tank was much a kind of failure in World War I. It was not reliable as most of the models had design flaws and also there was lack of belief among troops on its use in battlefield.
Inspite of failures it helped troops to pass trench and barbed wires.
In 1916, tank was introduced for the first time. Name of first tank was No.1 Lincoln Machine (also knows as "Little Willie") , which was built by British and designed by Sir William Tritton and Lieutenant Walter Gordon Wilson.
Apart from British army, French, American and German troop also introduced their tanks in first World War.