A score is a score is a score.......... but sometimes I see "performance score". What is this? A score with notes for the instrumentalists only? A score with written notes (text!!!) how to perform.
Primarily is means a conductor's score that is suitable for performance; sometimes with a binding that will allow it to lie flat on the podium and/or is large enough to be easily read during prformance.
A secondary meaning can refer to individual parts that are printed in a larger format for ease of reading by the musicians.