Originally founded in 1919 by Jack Cohen, the group has more recently diversified both geographically and into other retail areas, such as books, clothing, electronics and toys, as well as financial service and telecoms and internet service subsidiaries. This expansion in the nineties saw Tesco reposition itself from a low-cost retailer to one that appeals to many social groups by offering a range of own-label selections, from 'Tesco Value' items to its 'Tesco Finest' range. It operates a number of different sized stores, with Tesco Extra at one end of the spectrum, which are larger supermarkets that stock nearly all of Tesco's product ranges and a large range of non-food goods, to 'One Stop' stores which act as small convenience stores. The number of stores operated by Tesco have increased year on year, with forecasts predicting continued growth in the number of outlets. Following the economic downturn, larger grocery retailers have lost share, while cheaper alternatives, discounters in particular, have found favor among the British public. As such, Tesco is finally experiencing a return to growth in sales as the economy recovers.
The group also exists internationally with wholly-owned grocery retail operations in nine countries, in addition to interests in a number of other businesses and joint ventures with local partners. In terms of the group's revenue, however, a large majority is concentrated in the United Kingdom and Republic of Ireland. Tesco has been a leader in technological adoption: it enabled the first ever recorded online shopping transaction from home in 1984 and, to this day, remains the leading online grocery retailer in the country. Since 2014, the e-commerce net sales of Tesco have increased significantly and reached over six million U.S. dollars in 2021.