there are machines that just etch, like to add names an logos onto items.
The next step up will cut light materials, card stock, thin wood, or thin plastic (specific types).
These are often used as overlay or front pieces on a solid backing.
These are all hobbyist type machines, though some are very robust.
If you want to move up to cutting metal, you need a lot of information.
What alloys? What thickness? What max piece size?
Larger machines require cooling and gases. They are expensive to buy and to run.
This is why btrue suggests waterjet. If you are going after metals that would be my suggestion as well.
Your basic infrastructure (table, filters. low pressure pumps, gantry) can be used for multiple different cutting heads.
As you want to do more you buy a bigger high-pressure pump and nozzle, and you are in business.
Don't underestimate the use of waterjet.
Most of the paper goods that you buy are waterjet cut, and nearly all food (cookies, crackers, candy, and more) are also cut this way.
High pressure and very small jet will do wonders.
