Co-op traces its roots to the Rochdale Society of Equitable Pioneers, set up in 1844, and it's the food business of the Co-operative Group, one of the world's largest consumer co-operatives. The group is based at 1 Angel Square in Manchester. Wikipedia lists nearly 2,400 Co-op food stores, most of them small or medium-sized local shops, which makes it the UK's seventh-largest food retailer. Through Co-op Wholesale it also supplies more than 6,000 other shops.
Because it's a co-operative, Co-op is owned by its members rather than shareholders. Membership costs £1, and you get that back on your first shop in store when you choose your personalised offer. Members get lower prices on everyday essentials such as milk and bread, a choice of personalised offers every week, and a share of profits for a local cause they pick. They also get discounts on Co-op Funeralcare, Insurance and Legal Services, a vote at the AGM and presale tickets for Manchester's Co-op Live arena.
Member prices aren't available in independent co-operative societies, Co-op franchise stores, some Co-op Live concession stores or non-Co-op-branded shops, and prices online can differ. You can join online or in the Co-op App, and the digital membership card is ready to use straight away.