The B-flat major triad, more commonly called the B-flat major chord or simply the B-flat chord for short, consists of the notes B-flat, D and F. Here it is on the treble clef staff:
... and on the bass clef staff:
Here are both of the above chords on the piano:
As B-flat major triad, the B-flat chord consists of a major third plus a minor third. The interval from B-flat to D is a major third, while the interval between D and F is a minor third.
If the root of the B-flat chord—B-flat—is the bass note (i.e., the bottom note), then the chord is in root position:
If the third of the chord—D—is the bottom note, then the chord is in first inversion:
If the fifth of the chord—F—is the bass note, then the chord is in second inversion. (F is called the fifth of the chord because the interval from the root B-flat to F is a fifth.)
If the notes of a chord are played one after the other, the chord is said to be arpeggiated. Here are the standard fingerings for arpeggios of the B-flat chord. Make sure you learn these fingerings!
(If you don't understand the below notation, you should start with my How to Read Sheet Music course.)