Keeping kids in one place is like herding cats. Gates can help keep your toddlers off the stairs and out of trouble.
There are two basic types of child gates. Pressure-mounted gates don't take hardware to install and are easy to remove when the kids get older. Attached gates leave holes, which may not be appropriate in a rented home. Generally, attached gates are less likely to come loose and fall on the child.
Don't be lulled into thinking kids can't get past a gate. Kids are great learners and if they want to be free, they'll find a way. Child gates shouldn't be used in lieu of supervision.

Photo Courtesy of PriceGrabberInstalls in spaces from 70 inches to 144 inches (12 feet). This gate is 30 inches tall and will fit straight spaces or uneven walls.

Photo Courtesy of PriceGrabberThis is a modular system that can be extended to fit almost any space. It works on angles or straight across -- 29 inches tall.

Photo Courtesy of PriceGrabberFits around the fireplace to keep little ones away from the pretty flames.

Photo Courtesy of PriceGrabberA plastic gate with a window in the middle. It fits across openings as large as 42 inches.

Photo Courtesy of PriceGrabberIntended for stairs, the curved design allows a foot of room on the top step. Fits openings from 29 to 42 inches and swings open.

Photo Courtesy of PriceGrabberCorral the kids in the backyard (or the front yard).

Photo Courtesy of PriceGrabberThis metal gate fits spaces 28 to 72 inches wide. It swings open to allow adults to pass.

Photo Courtesy of PriceGrabberThis gate is soft for the kids. It secures in place with pressure so there's no hardware to mount, but it doesn't swing open and creates a trip hazard for adults stepping over it. This gate is 27 inches tall and fits doorways up to 60 inches across. Putting a pressure-mounted gate anywhere other than a doorway can damage walls.

Photo Courtesy of PriceGrabberThis gate installs without tools and swings out of the way to allow adults through.

Photo Courtesy of PriceGrabberThis wooden gate fits stairways up to 43 inches wide and includes hardware to prevent the gate from swinging out over the stairs.