After a wood is stained (or left natural), it's often treated for protection.
A soft, warm finish comes from waxes or oils, such as beeswax or mineral oil. They sink into the fibers and saturate the wood, providing a subtle, matte sheen. High-end wood varieties, like cherry and walnut, are often finished this way. Waxes or oils may need to be reapplied monthly or annually, depending on wear.
A hard, protective finish comes from shellac, varnish, lacquer, or polyurethane. This noticeable "shell" is typically high-gloss or semigloss. It doesn't need to be reapplied unless the piece is severely damaged.