The Rock and Steel types resist them because a normal person's hit against those elements is not very effective, as they are both hard. They're immune to the Ghost type and vice versa because a mortal and a ghost can't hurt each other.Trivia...
Many of the Normal moves (besides Odor Sleuth and Foresight) had no effect against the Ghost-type Pokemon. However, in Pokemon Go, instead of total immunity from your attacks, you get 0.39x damage from Ghost. In other words, you get around 60% damage from Ghost-type moves. Above all, ...
Clefable to Arceus. Not all of these Pokemon are pure Normal type, as some are half while others are secondary. Although Normal Pokemon may not have the same awesome appeal as other types do, they're statistically decent Pokemon and are the second most common type in the game, w...