In a score, what is the difference between a staff and a system?

Here are some things to consider:

• For lead sheets and scores with only one staff, the staff and system are the same.
• For scores with two staves (such as piano parts) there are two staves in each system.
• For a score with three staves or more, there are three staves or more in each system.

• Another way to tell the difference is when you press play in Sibelius or Finale, the playback line stretches to include all of the staves in the system.