The unit-specific quantity might be:

• "Descriptive: the factual value that some variable actually would take for unit i in the absence of intervention;" e.g., $Y_{i}$: "whether person i is employed ...
• Causal: the value some variable would take if a treatment variable D was set to a particular value d, producing the potential outcome;" e.g., $Y_{i}(d)$: "whether person i would be employed if they received job training)"
• Causal Difference ("A difference in potential outcomes): the effect of job training on the employment of person i"
• Caused by Multipel Variables: "An outcome that would be realized under intervention of more than one variable;" e.g.,
  • "A mediation claim about the outcome $Y_{i}(d, m)$ that unit i would realize if the treatment were set to $D = d$ and some mediator were set to $M = m$."
  • An interaction claim of "whether person i would be employed if they received job training and childcare."