DSLR

DSLR (Digital Single-Lens Reflex): A digital camera body featuring a reflex mirror mechanism for a true optical viewfinder (TTL) and compatibility with a vast ecosystem of interchangeable lenses.

The Digital Single-Lens Reflex (DSLR) camera is defined by its core reflex design: light travels through the main lens, hits a mirror, and is directed via a pentaprism to the optical viewfinder. This provides the photographer with a precise, through-the-lens (TTL) view. When the shutter fires, the mirror instantly flips up, allowing light to strike the large digital image sensor (e.g., APS-C or Full-Frame) for recording. This architecture, which largely replaced film SLRs in the 2000s, delivers superior image quality, fast phase-detection autofocus, and the critical advantage of a versatile, interchangeable lens system (like Canon EF or Nikon F-mount).

https://en.wikipedia.org/wiki/Digital_single-lens_reflex_camera