piano chord
D♭maj7
D♭1F3A♭5C7
Major triad with a major seventh: a half step below the root, an octave up.
Written the other way round it is C♯maj7 — the same twelve keys on a piano, a different piece of notation.
What is true of it
D♭maj7 is D♭, F, A♭ and C — 1, 3, 5 and 7 counted from D♭.
On an instrument that cannot reach all 4, the 5 goes first, in that order.