Routers are all about grooves. You can make straight, square grooves with a circular saw or a miter saw, but doing so takes a long time and it's hard to get the ends of the cut to look neat. You're out of luck entirely if you need a curved slot (say, for a roll-top desk cover) or one with a non square profile (such as those used for decorative moldings). If you're going to build furniture or cabinetry, you have to be able to make grooves and create profiled edges. In other words,
you need a good router.
The Two Types: Plunge and Fixed-Base
There are
two basic varieties of routers: plunge and fixed-base. Plunge routers allow you to make cutting-depth adjustments on the fly, without having to turn off the motor. Because you can move the router into position and then lower the bit accurately, they're great for blind dadoes and other slots that don't terminate at the edge of the workpiece. They also excel at cutting mortises and following patterns. Some folks don't like plunge routers because they tend to have higher centers of gravity than fixed-base routers of similar power, and are therefore more awkward to handle. However, this isn't a problem if you plan to mount your router in a router table, which you can buy for relatively little money or make in an afternoon.
Fixed-base routers are best used for jobs that don't require midcut adjustments to the depth of the cut. They're great for dado work, cutting rabbets, and putting decorative facings on edges, and D-handled versions can be turned on and off with a trigger switch so you don't have to take your hand off the router. Fixed-base routers also tend to be smaller, lighter, and less expensive than plunge routers. Actually, you can lock a plunge router at a certain depth and use it just like a fixed-base router. But unless you have a specific need for the adjustable-depth feature of a plunge router, you'll probably be very happy with a fixed-base router.
