Can someone please explain the Mitochondrial Eve to me simply?

While I have a basic understanding of the concept, the Mitochondrial Eve is a rather new idea to me. Can someone clear a few things up for me? I’m going to spew a combination of my understanding as well as questions.. bare with me! And feel free to correct ANYTHING about my perceived understand that I may be wrong about!

It is said that the Mitochondrial Eve and Y-Chromosome Adam lived roughly 140,000 years apart. And I also understand that she wasn’t a literal one women.

So, how does she reproduce?

How is it that if there were many “women”.. that we descend from but one? And when they say that we all share her mitochondria.. I thought we all have our own? (carried down from our mothers.. as the mothers mitochondria destroys the fathers upon conception)
I read on one website someone postulating that women are the base human form and that men are a genetic mutation of sorts (seeing as how men begin as women in the womb ie. nipples etc)

And if Eve was traced back further than Adam, could that possibly be viable? While that seems a bold claim, is there any possible truth to it?

Also, the term Mitochondrial Eve is fixed, but the women is not. As lineages dye out, the Eve moves forward a generation?

And, I’ve also read that there are strains of descendants that do not take after Eve.. but are a.) either too few and far between? Or b.) not in existence anymore?

Basically, can someone explain the big picture to me, without too much emphasis on the this detail or that? Because at this point, I feel like I could pass a “test” on the subject (Maybe? Maybe not? lol) because factually I get it. But I’m not grasping the bigger picture and able to picture it..

Thanks!! ^_