Many people have learned the word vagina to refer to the genitals of a person assigned female*, but the vagina is just one part of a more expansive area termed the vulva that also includes the clitoris, the labia, and the mons. More ways to enjoy sensation, and more specific ways to understand anatomy! Perhaps the prevalence of "vagina" is reinforced by the phrase "penis and vagina," making the vadge sound like the primary sex organ. But that downplays the role of the clitoris and all the rest, and we want to UPplay it because of all the pleasure that awaits when you explore the whole vulva! 

*And of course some people don't retain the identity they were assigned at birth throughout their lives, so even if they have the same body parts we're discussing, they might have different words they prefer.

Many people are worried that masturbation (or self-pleasuring, or whatever you call it) will "ruin" partnered sex for them. In fact it will likely make it even better, especially if they will share the info about their arousal and sensation preferences with partners, and those are great things to learn during solo play. This lets you indulge and explore the ways the right stimulation styles for you can help you reach new heights. And this is super-useful information to have when you are  enjoying sex with a partner or alone.

The clitoris functions very much like the penis—the two body parts grow from the same tissue. ​Similar kinds of stimulation tend to heighten arousal, and arousal is an important building block as you explore orgasm. (Not aroused enough = much lower chance you will come, or even enjoy the sex a lot!) While people can orgasm from varying kinds of stimulation, for AFAB people, it is much more common to reach orgasm when clit stimulation is central to their sex play.