Pots de crème refers to both a custard dessert and the traditional small pots with lids that you serve the custard in.
The custard is often flavoured with vanilla or chocolate.
The custard is a just barely firm baked custard. The proportions are usually 1 egg plus 5 egg yolks per 3/4 litre (24 oz / 3 cups) of milk.
The custard mixture is put into the pots de crème cups, and the cups baked in a water bath. The pots are covered with their lids during baking to stop a skin from forming on top of the custard. The cooking time is about 20 minutes.
The traditional pots de crème cups usually are very small, only holding about 100 ml (3 oz.) They have a single handle on the side. The lids also have something on top that acts as a handle to make it easy to lift them off.
Now, ‘colloquially’, many different types of small dishes are used to serve ‘pots de crème’ in. Modern ones tend to have no handles, and be straight-sided and clean in their design; they may also have no lid. By default, this is often a ramekin, which serves a dual purpose as also being multi-use.
The “crème” is made in something else and the “pots” merely used for serving.
There are also now commercial candy-like takes on the theme.
See also: Pots de Crème Day
Literature & Lore
The traditional special lidded pots are very collectible now.
The French don’t have a separate word for custard, so they call it crème.