How do you spell men's and women's toilets in English? What does W.C. mean?

The toilet can be a toilet or a washroom, and there is a male/female or female toilet in front to distinguish between men and women. A long time ago, there was a water tank in the toilet. When people mention the toilet, they think of it, so the toilet has become synonymous with the toilet. Later, for convenience, people replaced the toilet with the initials W.C..