Why is ref used?

Could you please elaborate on the purpose and significance of using 'ref' in the context you're referring to? Is it in programming, particularly when dealing with references or pointers? Or is it in the realm of financial transactions, where 'ref' might signify a reference to a specific asset or security? Understanding the exact context would help me provide a more accurate and relevant explanation of why 'ref' is used. Can you provide any additional details or clarify the specific application of 'ref' that you're inquiring about?