Vibrators - pretty much the first thing most people think about when they think about sex toys, but we tend not to think about how they do their thing.
A vibrator is basically an off-balance electric motor in a body-safe case. Yes, off-balance - most electric motors are designed to be properly balanced, but vibrator motors actually have a weight to make them wobble. The amount and location of the weight is what creates different feelings from different toys. A few vibrators use a much gentler "pancake" motor. Vibrators also contain a power source - most modern vibrators are powered by batteries, either replaceable or rechargeable. (The Magic Wand still requires a wall socket, but most women want to be able to take their vibrator anywhere, and a rechargeable version became available last spring).
That's the basics - a motor, a power source, and a case - but wait! Modern vibrators have all of those different speed and pattern options. If your vibrator has patterns, multi-function buttons then guess what - your vibrator is actually a computer. A very small, specialized one. (Vibrators with dials can get this effect without computing power, but most vibrators have buttons). It contains a small printed circuit board that controls motor speed in a very refined way. Remote control vibrators, of course, also have a way to receive a signal.
Vibrators have come a long way - and they're likely to go a lot further. From something initially designed to treat "hysteria" and for a long time hidden, vibrators have become kind of cool, mostly because of feminism. Companies are now applying all kinds of technology and new ideas - including prostate massagers for men.
What kind of new things are out there? Vibrators that are designed to feel like oral sex have become a thing - both for applying to a clitoris and for applying to a penis. In 2014, a company called Eva, crowdfunded a "clitoral stimulator" that's designed to stay in place on its own during sex. New toys in 2016 included a vibrator that fits inside your panties, a vibrator that bends into the exact shape of your, you know, parts, and a vibrator that's designed to train your Kegel muscles, which can help with better sex. Oh, and there's an app for that - some vibrators can now be controlled by your smartphone. Or your partner's. One comes with a smartwatch app that reads your heartbeat and adjusts the vibrator accordingly.
In other words, a vibrator is not just a motor, a battery, a case and some buttons - not any more. Highly advanced technology is making the "humble" vibrator more and more...intelligent.