Force Sensors & Load Cells

A load cell is a type of force sensor that converts the deformation of a material, measured by strain gauges, into an electrical signal. The most common type of load cell uses a bending beam configuration. As force is applied to the beam, it bends slightly and this bending/strain of the beam material changes the electrical output of the strain gauges mounted on the material. 
There are other types of force sensors available, such as piezoresistive force sensors, which measure force differently. A piezoresistive force sensor measures a compressive force directly instead of correlating the strain of a beam to force applied.