Seal before or after staining?

[Mattatooi]

Have wooden window sill inside. Sanded it back and removed previous sealant from sill to frame. I am applying a wood stain to it. Should I stain before applying seal and what is best to use here. Caulk or silicone ?

If I was painting it, I would use Caulk and apply it before top coat. But as its stain I am thinking this will be different process?

Cheers