Not everyone uses the same musical terms.  The Mighty Maestro lets you choose either the notation commonly used in the US/Canada and the definitions generally used around the rest of the world.  You may switch between these different styles at any time.

US, Canada UK, Australia, NZ and elsewhere
Quarter Notes Crotchets
Eighth Notes Quavers
Sixteenth Notes Semiquavers
Half Notes Minims
Whole Notes Semibreves
Measures Bars
Staff Stave