Solid wood and engineered board behave differently
The materials here run to poplar, yellow poplar, ash and parawood on one side and MDF on the other, with ceramic and marble appearing as tops rather than carcasses.
Solid wood moves with humidity, which a bathroom has a great deal of, and it can be sanded and refinished when it does. An engineered board does not move and cannot be refinished. Neither is the better answer in the abstract: one tolerates change and the other refuses it.
Width is how these are sold
The sizes here are single figures: 36, 60, 30, 48, 72, 24 and 84 inches, with a few odd ones between them.
Those are the standard cabinet widths, and a vanity top is made to match them. Starting from the width is the only order that works, because the top, the basin and any splash all follow from it. Vanity tops and vanity backsplashes carry the pieces that go on.
Depth is what catches people out
Width gets quoted and depth gets forgotten, and depth is what stops a vanity fitting.
A cabinet projecting 21 or 22 inches from the wall has to clear a door swing, a lavatory and whatever else is fixed in a room that is frequently the smallest in the house. A vanity that fits the wall and blocks the door is the commonest failure, and it is entirely avoidable with a tape measure.
The heights cluster just under 35 inches
The height figures here sit between 33 and 34 1/2 inches to the top of the cabinet.
That is the modern comfort height. Older bathrooms were built around 30 to 32 inches, a standard set when basins were used by children as often as adults, and the difference is noticeable in use. It also matters when replacing a vanity in an older house, because the plumbing behind the wall was set for the old height.
What comes with it and what does not
A vanity is really three products: a cabinet, a top and a basin. Some listings include all three and some are the cabinet alone.
That is the first thing to establish on any given product page, because it changes what still has to be bought and it changes the comparison between two pieces that look similarly priced. A cabinet with a stone top and a cabinet without one are not the same purchase.
Ceramic and marble appear as tops
Ceramic and marble show up in the material field here, and they are almost never the carcass.
A ceramic top is a single moulded piece with the basin formed into it, so there is no join between bowl and counter at all. A marble one is cut from slab with the basin dropped in or mounted under. The first is seamless and fixed; the second can be replaced independently of the bowl.
The finishes are joinery finishes
White and bright white lead, then honey oak, light natural oak, mid-century walnut, gray and a smokey celadon.
Those are paint and stain names rather than tile finishes, and they describe the part of a vanity that is hardest to change. A stone top can be replaced and a basin swapped; the cabinet and its color are the object itself.
Freestanding, wall hung and console
Most of these stand on the floor, with a console group and a few wall mounted pieces among them.
A floor standing unit hides the plumbing and gives the most storage. A wall hung one leaves floor visible underneath, which makes a small bathroom read larger, at the cost of putting the whole weight of a cabinet and a stone top onto a wall. That last part is a structural question rather than a decorative one.
Where the rest of the range is
Single vanities and double vanities sort the same products by basin count, and vanities is the smaller own-brand set.
Bathroom faucets carries the spouts, and the basin decides which of them will work: a vessel sitting on top of a counter raises the rim several inches and needs a taller faucet than a bowl dropped into the top. That is a decision to make alongside the vanity rather than after it.