A reach-in is the workhorse storage cabinet of a commercial kitchen. It stands upright, usually around two metres tall, with one to three solid or glass doors and adjustable shelves inside. Most come with the refrigeration system built in, so you plug it into a socket and it runs. Versions exist as refrigerators, freezers, dual-temperature cabinets with separate compartments, and convertible cabinets that can be switched between chilling and freezing.
What separates a commercial reach-in from a household fridge is how it handles abuse. Doors open dozens of times an hour during service, warm pans go in, and the kitchen around it may sit at 40 °C or more in an Indian summer. A commercial unit has a larger refrigeration system, forced-air circulation to recover temperature quickly after the door closes, stainless or coated steel that tolerates daily wiping, and shelves rated for heavy GN pans and crates.
Take a 60-cover restaurant in Pune. A two-door reach-in near the prep area holds marinated chicken, paneer, dairy and pre-cut vegetables for the day, while the bulk stock sits in a freezer or a cold room further away. The reach-in keeps the most-used items within a few steps of the cooks.