The definition in the URL below for feriado proporcional is slightly different than what you found. Basically, if you don't work for an entire year for a company, you don't get vacation but you accumulate vacation days. So if you leave early, you get a payment based on the number of days accumulated.

Feriados pendientes is, as I understand it, days that you can actually take as vacation but, because you were fired or quit, won't.