Very much so. I-ICO yindawo yokugcina egcina ii-bitmaps ezisikwere ezininzi ngaxeshanye (16, 32, 48, 64, 128 ne-256 px) ukuze ii-Windows kunye nee-browsers zingakhetha ubungakanani obufunayo. That determines both the headroom available and whether the saving costs you anything in fidelity.
Yes — i-ICO yi-stack ye-square bitmaps, hayi umfanekiso omnye, ngoko ke ukwenziwa kweenkqubo kuxhomekeke kwi-stack kwaye i-Windows iyaqhubeka nokukhetha ubungakanani obufunayo. It is worth knowing before you overwrite an original you might need again.
Ingaba i Cima ICO iya kunyusa ubunjani be ICO icons yam?