The word as used in the current context originated in the Middle Ages. It comes from the Old French atellier meaning "to arrange", and attillement meaning "equipment". From the 13th century an artillier referred to a builder of any war equipment, and for the next 250 years the sense of the word "artillery" covered all forms of military weapons. Older engines like the catapult, onager, trebuchet and ballista are artillery, but the modern term really dates from the mid 15th century with bombards and then cannon.
Bombards are the earliest of gunpowder artillery, distinguished by their lack of a field carriage, immobility once emplaced, highly individual design, and noted unreliability. The use of the word cannon marks the introduction of a dedicated field carriage with axle, trail and horse-drawn limber - this produced mobile field pieces that could move and support an army in action rather than being found only in siege and static defences. Cannon were always muzzle-loaders, casting technology having standardized and removed the often dangerous breech-loading design.
Cannon operation was still a complex technical task, often undertaken at high-speed and in stressful conditions, where a mistake could easily be lethal. The field carriage eased movement in general, but traverse and elevation were still very limited and slow - the crew ramming levers, handspikes, to force a movement of a few degrees. Larger movements were by brute force shoves of the entire unit, as was repositioning after recoil, an extremely enervating task.
The combining of shot and powder into a single unit, a cartridge, occurred in the 1620s with a simple fabric bag, and was quickly adopted by all nations. It speeded loading and made it safer, but unexpelled bag fragments were an additional fouling in the gun barrel and a new tool - a worm - was introduced to remove them. Shells, explosive-filled fused projectiles, were also developed - problems with the fuses were extremely common. The development of specialised pieces - shipboard artillery, howitzers and mortars - was also begun in this period. More esoteric designs, like the multi-barrel ribaudequin, were also built.
The 17th century book by Polish-Lithuanian Commonwealth inventor Kazimierz Siemienowicz "Artis Magnae Artilleriae pars prima" ("Great Art of Artillery, the First Part". also known as "The Complete Art of Artillery") was one of the most important contemporary publications on the subject of artillery. For over two centuries this work was used in Europe as a basic artillery manual.
Oddly the development of cannon almost halted until the 19th-century, improvements in metallurgy, chemistry, manufacturing, and so on, did not alter the basic design and operation of a cannon. From the 1860s artillery was forced into a series of rapid technological and operational changes, accelerating through the 1870s and on. The main impetus was the improvements in small arms, which certainly had not spent 200 years in the doldrums. Artillery could no longer be deployed in the battle line, the large crews and stocks of ammunition were vulnerable to rifle fire, but had to either become smaller, lighter, more mobile and stay with the troops or get much further away. The second type, using indirect fire, forced the development of the technologies and doctrines that produced modern artillery.