What is the full meaning of iota?

Could you kindly elaborate on the comprehensive significance of the term "iota"? I'm particularly interested in understanding its etymological origins and any contemporary applications it may have in the realm of cryptography or finance. Could you also provide any examples or contexts where this term is frequently used? It would be greatly appreciated if you could explain this in a concise yet informative manner, keeping the word count to around 300 words or less. Thank you in advance for your assistance in clarifying this matter.