The ability to deliver the immense destructive power of artillery barrages down on opposing forces had a huge impact on the battlefield. It forced the adoption (or re-adoption I'd argue) of new infantry tactics that emphasized dispersion on the battlefield, and the development of new artillery methods such as modern counter-battery fire based on map-firing, sound ranging and flash spotting, and aerial reconnaissance. The massive use of artillery in 1916 brought an end to Trench Warfare as we know it, as I argue [here] (https://np.reddit.com/r/AskHistorians/comments/3dxlav/what_were_the_conditions_during_ww1_in_the/ct9udmc).

As to 'stopping the use of Calvary charges', your teacher was very much wrong. Stephen Badsey, David Kenyon and the Marquess of Anglesley have written extensively on the British Cavalry in WWI, and have demonstrated that utilizing their own artillery and machine guns, and trained to fight on horseback and on foot, they were able to operate effectively on the battlefield in numerous cases in 1914, 1916, 1917 and 1918. Cavalry was still widely used in WWII, notably in the Red Army's Cavalry Mechanized Groups.

Yes, I have written about artillery in WWI here and again here

Simply put - The increase in firepower due to the introduction of rapid firing artillery, equipped with recuperators, and firing high explosive and fragmentation shells was an absolute game changer.

Artillery forced the troops into a subterranean existence as the only means of survival. Any advance had to finish with the digging new trenches if the attacking troops wished to survive the inevitable bombardment that followed.

Any attack on an entrenched position required extensive artillery preparation if the assault was to be successful, but to prepare enough guns and ammunition for the bombardments gave away any element of tactical surprise, and what's more the bombardments cut telephone lines and rendered any form of line-of sight and voice communications impossible. Thus an attacking force became immediately leaderless, its generals impotent, at the very moment they were needed most. Furthermore, any infantry assault that outran its own artillery would be cut to ribbons.

This was the cause of the initial 'stalemate' on the western front, and it took a revolution in the scientific application of artillery to finally break the stalemate - only when artillery technology had advanced to the level that it could smash in and smash through any given trench system at will, would open warfare finally return.