A grocery store or grocer’s shop is a retail shop that primarily sells food, either fresh or preserved. Large grocery stores stock significant amounts of non-food products, such as clothing and household items, blurring the line between grocery stores and supermarkets.
In Canada, the United Kingdom, and the United States, supermarkets and convenience shops are sometimes described as grocery businesses, groceries or simply grocers.
Small grocery stores that mainly sell fruits and vegetables are known as greengrocers (Britain) or produce markets (U.S.), and small grocery stores that predominantly sell prepared food, such as candy and snacks, are known as convenience shops or delicatessens.
Some groceries specialize in the foods of a certain nationality or culture, such as Chinese, Italian, Middle-Eastern, or Polish. These stores are known as ethnic markets and may also serve as gathering places for immigrants.
Beginning as early as the 14th century, a grocer (or “purveyor”) was a dealer in comestible dry goods such as spices, peppers, sugar, and (later) cocoa, tea, and coffee. Because these items were often bought in bulk, they were named after the French word for wholesaler, or “grossier”.
This, in turn, is derived from the Medieval Latin term “grossarius”, from which the term “gross” (meaning a quantity of 12 dozen, or 144) is also derived.
Source : Wiki