The staff is simply the five parallel, horizontal lines where notes, clefs, time signatures, and everything else musical is placed. If your talking about more than one staff, the correct nomenclature is “staves”.
If you play piano you’ll see two staves stacked on top of each other. Generally the left hand plays the top staff in treble clef, and the right hand plays the bottom staff in bass clef. These stacked staves combined are called the “grand staff”.
A single staff:
Simple enough right?
