Key light — the main source in a setup, the one that defines where shadows fall. Fill light — a secondary source that lightens shadows without eliminating them; the key-to-fill ratio sets the contrast of the image.
Back light (or hair light) — a source placed behind the subject to create separation from the background. Rim light — a harder variant that traces the subject's outline.
Strobe / monolight — an electronic flash unit; a monolight has its power supply built into the head, while pack systems share one supply across several heads. Flash duration — how long the burst of light lasts; shorter durations freeze motion better.
Softbox — an enclosed modifier that produces soft, directional light. Umbrella — a cheaper, broader modifier that spills light widely. Grid — a honeycomb insert that narrows a light's beam.
Seamless paper — backdrop paper sold in long rolls and standard widths, swept down in a curve so no horizon line shows. C-stand — the heavy, modular Century stand used to hold lights, flags, and modifiers.
Tethering — connecting the camera to a computer so frames appear on a large screen immediately after capture. Light meter — a handheld device that measures flash output so lighting ratios can be set precisely.