EF lenses are a series of interchangeable camera lenses designed for use with Canon digital single-lens reflex (DSLR) cameras. The "EF" stands for "Electro-Focus," indicating that these lenses use electronic connections to communicate with the camera body, allowing for features like autofocus and image stabilization. These lenses come in various focal lengths and types, including prime and zoom options, catering to different photography styles. EF lenses are known for their high-quality optics and versatility, making them popular among both amateur and professional photographers.