Usually they involve paying a small amount of mana to make a larger amount of mana of that same color, which is useful when you want to cast a large spell (or multiple smaller ones) that same turn
Over time, Magic has made newer takes one it, like Magus of the Moon, which puts the effect on a creature, or Zhao, the Moon Slayer, which forces nonbasics to enter tapped and can later fully turn them into mountains once its powered up
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It doesn't copy whether that token is tapped or untapped, whether it as any counters on it or any Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, or so on
A giant sinkhole with a waterfall pouring down and a jungle surrounding it, and Koraidons just perched up high overlooking it all
The strength of what you tutor for is going to scale based on how much mana you have available and what the game state is