So in no way am I an expert on either rock climbing or ice climbing, however, I’ve tried both over the summer and I can give my beginners opinion to a fellow beginner.
The Obvious Difference
The main difference between the two is the object you’re climbing, rock and ice, which means there will be big differences to the way you climb. For instance, with rock climbing you look for holds in the walls to grab onto and then pull yourself up with, but with ice climbing you slam your axe into the wall until it is still then you dig your crampons in at 90 degree angle so it stays, and you walk up the wall straight. There is a huge difference with the way you move your body up the wall. I found ice climbing more strenuous as you have to be really careful to make sure your feet stay parallel to the floor where as rock climbing you just need to find a hold.
With rock climbing you have ropes and a belayer, whereas with ice climbing you need the ice axes, crampons, special boots, warm clothing. and a helmet with an eye guard, very important, ice falls all the time! This would make ice climbing more expensive to do as a hobby as you would have to buy the equipment yourself.
In my novice opinion, I was sooooo tired after ice climbing, which makes me think it involved more strength (for me). Mainly because I was constantly trying to keep myself from falling, as you had to keep your feet straight otherwise I’d slip straight off the wall. Plus I only got up there once, whereas with climbing I’m happy to be up there constantly.