Dsus2sus4 is D, E, G and A. It leaves out the 3rd and includes both the and .
Without a or , Dsus2sus4 is neither major nor minor. In jazz, sus chords can stand without resolving.
To hear what the adds, start with .
The 2nd drops two frets to a repeated root. The root, 4th, and 5th stay put.
Also written Dsus2/4 or D suspended 2nd and 4th.

Stack the four notes closely, then drop the second voice from the top an octave. It typically lands on four adjacent strings: the guitar’s workhorse voicing.
That result, 5–R–3–7, is the shape usually meant by drop 2. Named by its bass note, as the inversions are here, it is the 2nd inversion.
In which keys. Every note of Dsus2sus4 belongs to C major (the ii), D major (the I), D minor (the i), E minor (the ♭VII), F major (the vi), G major (the V), A minor (the iv) and B minor (the ♭III).
Contains Dsus2sus4 and adds major third, sixth and major seventh.
Adds major third, sixth and flat seventh. The flat seventh pushes the sound toward a dominant chord.
Contains Dsus2sus4 and adds minor third, flat thirteenth and flat seventh.
Contains Dsus2sus4 and adds minor third, sixth and flat seventh.
Contains Dsus2sus4 and adds minor third, flat thirteenth and major seventh.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.