What is a router used for in woodworking?

Router: woodworking power tool that uses a high-speed spinning bit to cut, shape, and profile materials. Operation: motor spins bit at 10,000-30,000 RPM; multiple bit shapes create different profiles; can be handheld (with both hands on side handles) or mounted upside-down in a router table (bit projects upward through a hole, workpiece slides over surface). Functions: EDGE PROFILING for decorative shapes like round-over, ogee, cove, bead, chamfer on furniture edges; DADO or GROOVE channels in wood for joinery (shelves into bookcase sides, drawer bottoms); RABBET (step cut along an edge); MORTISE (square holes for joinery); HOLLOW OUT areas like sign letters, trays; FLUSH TRIM (trim laminate or veneer flush with substrate using flush-trim bit, bearing rides on substrate, cutter trims overhang); TEMPLATE WORK where bit follows a template edge to reproduce shapes; JOINERY (dovetail jigs with router create precision dovetails, box joints, locking joints). Router bits come in hundreds of profiles; carbide-tipped for durability; shank sizes 1/4 inch or 1/2 inch (1/2 inch for larger bits and better stability); BEARING on bottom guides cuts along template edges; HEIGHT adjustment of router controls depth. Router types: FIXED-BASE (set depth, plunge into work); PLUNGE ROUTER (spring-loaded, can plunge into middle of a workpiece); COMPACT or TRIM ROUTER (palm router, small one-handed); ROUTER TABLE (large stationary setup with router mounted upside-down). SAFETY: eye and hearing protection (loud); push wood AGAINST rotation of bit (climb-cutting can grab and pull workpiece, light cuts only); take multiple shallow passes for deep cuts; use push pads or push sticks for narrow stock; clamp work or use fence; never adjust running router; unplug to change bits; long sleeves and loose clothing are HAZARDS because they can wrap around bit; check bits for damage before use. OTHER POWER WOODWORKING TOOLS: CIRCULAR SAW (handheld circular blade for straight cuts in lumber and plywood); MITER SAW or CHOP SAW (for angled cross-cuts; sliding compound miter saw most versatile); TABLE SAW (workhorse of woodworking shop for rip cuts, crosscuts, dadoes); JIGSAW or SABER SAW (handheld reciprocating blade for curves); SCROLL SAW (fine curves and inside cuts); BAND SAW (continuous loop blade for curves and resawing); JOINTER (flattens one face and squares one edge); PLANER or thicknesser (uniform thickness); DRILL PRESS (vertical drill for precise holes); SANDERS (random orbit, belt, drum, spindle).