Keeping question quite simple, I don't know much about measurings, so how many cups make 218 grams, and also when u say for example a cup what should be the size of that cup?
Please follow this table as a reference when converting grams to cups or vice-versa https://www.allrecipes.com/article/cup-to-gram-conversions/
See this link for more information about cups and its standards https://en.wikipedia.org/wiki/Cup_(unit)
Grams of what?
Grams is a measure of weight (actually mass, but we'll assume you are cooking on earth).
Cup is a measure of volume.
Different substances have different density, and powdered items like flour can be more or less packed or settled.
To confuse things a bit, in the USA we have ounces (weight) and fluid ounces (volume). When we talk about volume in fluid ounces, a shorthand is to just say ounces.
One cup = 8 (fluid) ounces.
But that 8 fluid ounces can be:
approximately 4.5 ounces of flour, really 120-130 grams, depends on the grind and the sift
approximately 8 ounces of water (that is where fluid ounces came from)
a bit more than 8 ounces butter