Values are similar to data names for fields but instead are used for choice options in a choice field types (Single Choice, Multiple Choice, Yes/No, and Classification Set fields). Within Fulcrum, the label of the selected choice is visible, but when you go to export the data out of Fulcrum the value is what is included in the exported data. This allows you to populate the choice option label with human-friendly text while still storing the value that your system uses to represent a choice option.
Note: Values are what are pulled into calculation expressions. This can help with running calculations where the label represents a numeric value.