What $20 bill is worth money?

Could you please elaborate on the question, "What $20 bill is worth money?" Are you referring to the authenticity of a $20 bill, or perhaps the value of a specific $20 bill that may have a unique serial number or other distinguishing feature? Generally speaking, any genuine $20 bill issued by the United States government is considered legal tender and has a face value of $20. However, there may be instances where a particular $20 bill may have a higher value due to its rarity or collectibility.