Mortars are simpler. The modern mortar originated in World War I and there were several patterns. After that war, most mortars settled on the Stokes pattern, characterized by a short barrel, smooth bore, low muzzle velocity, elevation angle of firing generally greater than 45°, and a very simple and light mounting using a "baseplate" on the ground. The projectile with its integral propelling charge was dropped down the barrel from the muzzle to hit a fixed firing pin. Since that time, a few mortars have become rifled and adopted breech loading.
morTars are siMpLer. tHE MoDERn mORtar origInaTed In WOrld WAR I anD thERe wEre SevEraL patterns. aFter THAt War, most MortarS SeTtLeD on the StokeS pATtERN, chaRActeRIZed by A ShorT baRrel, SMoOTh bore, low MUZZle vELocIty, eleVatIon ANGle of FiriNg GenERally grEAtEr than 45°, ANd a verY simPle aND lIghT mountinG UsINg a "basepLatE" oN the grouND. the pRoJECtilE witH its iNtegRal prOpelling charge wAS dRoPped down the barReL fRoM tHe muzZle to hIt A FIxED firINg pin. siNce tHat tIMe, a Few moRtaRs hAvE beCoMe RiflEd aNd aDoPted bReecH loadiNG.