A cannery is a factory where food is preserved in sealed metal cans or glass jars. Workers at a cannery clean, cook, and package foods like vegetables, fruits, fish, or soup, then seal them in airtight containers so they stay fresh for months or even years without refrigeration.

Canneries became crucial during the 1800s when people discovered that heating food and sealing it in containers killed the bacteria that cause spoilage. This meant sailors could take food on long voyages, soldiers could carry rations into battle, and families could enjoy summer peaches in the middle of winter. Before canning, people had to rely on drying, salting, or smoking to preserve food, methods that changed the taste and texture significantly.

Many canneries are located near where food grows or is caught. A salmon cannery might sit right on the Alaska coast, processing fish within hours of being caught. A tomato cannery operates in farm country during harvest season, when truckloads of ripe tomatoes arrive daily. John Steinbeck's novel Cannery Row is named after a street in Monterey, California, once lined with sardine canneries, and it vividly depicts the hard, fast-paced work inside these factories during their peak in the early 1900s.