The word vulva refers to the external genitals. The word vagina refers just to the internal shaft. Neither of these terms, nor any of the slang for female genitals, accurately reflects the entire sexual system.
The vulva includes the labia, the clitoris and the area around the entrance to the vagina. The vulva is where most women experience the most pleasure, especially the clitoris. Our Guide to Fingering is your stroke-by-stroke video guide to pleasure the entire female sexual system, including clitoral stimulation and internal vaginal and g-spot stimulation.