APS-C stands for "Advanced Photo System type-C," which is a sensor size commonly used in digital cameras. It measures approximately 22.5mm x 15mm, making it smaller than a full-frame sensor but larger than a typical point-and-shoot camera sensor. This size allows for a good balance between image quality and camera size, making it popular among both amateur and professional photographers. Cameras with APS-C sensors often provide a crop factor of about 1.5x, meaning that a lens will appear to have a longer focal length compared to its full-frame equivalent. This feature is beneficial for wildlife and sports photography, as it allows photographers to capture distant subjects more effectively.