Rebar, a shorthand name for reinforcing bar, are steel bars used inside the pours of concrete and masonry structures in order to strengthen the final product as it is put under tension. Rebar is necessary due to the composition of concrete; concrete has significant strength when it is under compression (when it is pushed together) , however has low tensile strength (when it is stretched). Steel rebar supports tensile strength of the structure.
Concrete structures are inherently complex. Because of this, rebar needs to be cut and bent to fit very specific plans. Rebar cutters and benders are machines meant for this exact task. Generally electric/hydraulic driven, cutters use a shearing action to cut through rebar of different gauges. Most cutters are designed to be portable and hand-held. Rebar benders are typically electric or electric/hydraulic and use tooling to determine the angle of each bend. Though some benders are small and hand-held, most are free-standing machines. Combination cutter/benders are very common machines on concrete construction sites as well.