What is the difference between pliers and an adjustable wrench?

Tool function distinctions matter: using pliers to turn nuts and bolts damages the corners of the fastener (causing rounding/stripping). Use the right tool for the job. PLIERS types: SLIP-JOINT PLIERS have adjustable opening with two positions for general grip, holding nails, light-duty bending; the basic hardware-store pair. NEEDLE-NOSE PLIERS have long thin tapered jaws for reaching into tight spaces, manipulating small parts, bending wire. DIAGONAL CUTTERS (dikes, side cutters) are for cutting wire and small pins. LINEMAN PLIERS have large square nose for cutting near the joint and gripping flat surfaces for pulling/twisting wire; electrical work standard. TONGUE-AND-GROOVE or CHANNEL-LOCK PLIERS have multiple width adjustments; great for plumbing and large fasteners. LOCKING PLIERS or VISE-GRIPS clamp onto workpiece and lock; substitute for vise in field work. CRIMPING PLIERS are for crimping electrical terminals. WIRE STRIPPERS are for removing insulation from electrical wire. WRENCHES: OPEN-END WRENCH has U-shaped opening on each end sized for specific fastener; slips on and off easily but only contacts two of six flats (corners can round). BOX-END (closed-end) WRENCH fully encloses fastener with 6 or 12 points; better grip on six flats. COMBINATION WRENCH has open end one side and box end other (same size); most useful general design. ADJUSTABLE WRENCH (Crescent) has sliding jaw; one wrench fits many sizes; less secure than fitted wrench; can slip and round fasteners under high torque. PIPE WRENCH (Stillson) is toothed and adjustable; bites into round pipe surfaces; for plumbing; damages finished or hex fasteners. SOCKET WRENCH with socket and ratchet is most efficient; socket fully encloses bolt; ratchet allows rapid back-and-forth turning. TORQUE WRENCH measures applied torque; click-type clicks at preset value, beam-type shows pointer on scale; essential for engine bolts, wheel lug nuts, critical fasteners. ALLEN or HEX KEYS are L-shaped or T-handled for hex socket screws. PROPER WRENCH USE: pull toward you whenever possible (safer if wrench slips); always seat fully before applying force; choose size to match exactly; use fitted wrenches for high torque, adjustable for accessibility; on rusted fasteners use penetrating oil first. Metric sizes (mm): 8, 10, 12, 13, 14, 15, 17, 19, 22, 24 common. SAE fractional inches: 7/16, 1/2, 9/16, 5/8, 3/4, 13/16, 7/8 common.