Toilets & Bathrooms in UK & US

A bathroom is what you find in your house with a bathtub and toilet. A toilet is what you find in public places which is just a receptacle for the body's waste matter, usually with a supply of water for washing this away, and a sink. In British English toilet is generally acceptable but lavatory and WC (becoming old-fashioned except when talking about the plans of a house) are also used. Loo is a fairly common informal word. Public convenience is the formal expression for a specially built public lavatory, esp one in a public place. Quite generally in restaurants and other public places, the question is "Where is the ladies'?" or "Where is the gents'?" - the word "toilets" is understood but usually omitted.
In the US, it's "bathroom" in a home and "restroom" in a public facilty (like a restaurant, etc.). In public, you also refer to the ladies' room or the men's room.

Toilet-paper is paper for use in a toilet.
Toilet-roll is a roll of toilet-paper.
Toilet powder is a fine powder for spreading on the body (as after bathing).
Toilet soap is a mild soap, often coloured and scented, used for washing oneself.
Toilet-water is a type of perfumed liquid for the skin.
The toiletries are articles, such as toothpaste or a hairbrush, used in personal grooming or dressing. They may also include objects or cosmetics used in making up.
A toilet bag is a waterproof bag (usually made of plastic) for holding bathroom items and other personal hygiene equipment (soap and toothpaste etc.) when you are travelling. It may also be called washbag or sponge bag. A toilet bag specifically for men may be called a dopp kit.