The standard grips this chord is usually shown with.
Bm is B, D and F#, a minor triad. The shape this page opens on is written x24432, lowest string first.

Also written Bmin, B- or B minor. The same chord either way; which spelling you meet depends on who wrote the chart.
There are 8 common shapes for Bm on the guitar, and 50 derived voicings in 2 families.
In which keys. Every note of Bm belongs to D major (the vi), E minor (the v), F# minor (the iv), G major (the iii), A major (the ii) and B minor (the i).
The common shapes, written lowest string first: x24432, x5443x, 7544x7, 799777, xx9777, x-x-9-11-12-10, x-x-12-11-12-10, x-14-12-11-12-x.
Triad. Three notes across one string set. Bm has xxx432, 220xxx, x2443x, xx0432, 2204xx, xx4432, xx443x, x5443x.
Open string. An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful. Bm has xx0402, 2x040x, x2040x, 7x040x.
The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.