A Shavette is basically a straight razor, a shaving tool that looks more like a barber’s knife than a regular safety razor from Gillette or Wilkinson.
The first main difference is price. The Shavette is much cheaper than a straight razor. That is good for you, and that makes the Shavette a great starting place if you want to shave more like the pros but don’t want to hand out that much cash to get started.
Another difference is the blade. A shavette razor uses disposable blades (like regular razor blades that you throw away after a couple of uses). This means that you have to replace your blades after 5 to 10 uses, when it gets unsharp. The straight razor works more like a knife that you have to sharpen with special tools. It is hard to get a straight razor to be as sharp as a Shavette, so if you want a really close shave I guess the Shavette should do a better job. Professional barbers also argue that is more hygienic to use disposable blades, but for home use that argument is not worth much.
If you have sensitive skin, I would recommend using a shavette instead of a straight razor.