Sensor format refers to the physical size and shape of a camera sensor, which plays a crucial role in determining image quality and performance. Common formats include Full Frame, APS-C, and Micro Four Thirds. Each format has different dimensions, affecting factors like depth of field, low-light performance, and field of view. The choice of sensor format can influence the type of lenses that can be used and the overall size of the camera system. Larger sensors typically capture more light, resulting in better image quality, while smaller sensors may allow for more compact camera designs.