...Climbing on snow and/or ice is technically much "easier" than climbing on rock, but less safe :
while on rock grips and footholds are already there and you have to learn the better use of them, on snow you can decide the lenght of your steps and use some gear to improve the balance of your body : i.e. cutting footholds with an iceaxe, creating grips using an ice-hammer and putting hard the points of iceaxe and crampons.
Even the insertion of pegs is easier: you don't need to find a crack to fit :
in snow or ice the only need is to keep the correct balance, always hoping that snow or ice will not crumble.
Giving a look to some comments to photos shot while climbing on snow and/or ice slopes I've seen that there is a lot of confusion for the not "authorized personnel" (inexperienced sound bad ...)
here a simple starting point ...
of course one thing must be clear in the minds of the aspirant climbers : the finest is the mountain the steepest it is, and a minimum of experience is needed :
if you feel unsafe on a 40° slope and have to descend facing the slope you'd better avoid snow and ice !
easy here under means that an experienced climber can move without paying attention to his steps, while an inexperienced one could get very stressed at it ...
... and, not to be under underestimated, while climbing on difficult routes (over 55°) when iced, you can hardly take even a moment of rest (even belaying is "hard") : so be very trained is a very important feature to reduce risk factors.
a simple table
|between||and||difficulties||kind of "ground"||gear||with skis|
|0°||30°||F - walk up||normally good snow||no gear required||normal skill|
|30°||40°||PD - easy||normally snow||iceaxe useful||good skiers|
|40°||50°||AD - middle||sometimes iced||iceaxe and crampons||extreme skiers|
|50°||60°||D - difficult||often iced||ditto + some pegs||the best|
|60°||70°||TD - very difficult||ice||technical gear||suicide|
|70°||90°||ED - extreme||ice||technical gear|