what does cf. mean

The abbreviation "cf." stands for "confer" or "compare" in Latin. It is used in writing to refer the reader to other material to make a comparison with the topic being discussed. For example, in a scientific paper, "cf." might be used to suggest a specimens membership of the same genus or possibly of a shared higher taxon. In legal writing, "cf." is a signal indicating that the cited source supports a different claim (proposition) than the one just made, and it is worthwhile to compare the two claims and assess the difference. In some cases, "cf." may also be used as an abbreviation for "cost and freight". On Instagram, "CF" may stand for "Close Friends".