The first obvious area in which businesses have changed is the use of technology. Businesses in the Renaissance were labor intensive, with manufacturing mainly done by hand. This limited economies of scale and productivity.
Transportation was much slower and less reliable. Although global trade in valuable items certainly existed, with journeys between continents typically running to months rather than days, and quite hazardous, with both pirates and weather resulting in frequent loss of cargoes, globalized supply chains were generally not feasible, nor the modern types of outsourcing and offshoring. Even within a country, it might take several days to move items from one city to another.
Communications were much slower in the Renaissance, and mass media did not exist. This meant that business cycles were much slower and that business success depended more on local roots and word of mouth.
There were a far smaller number of financial instruments and types of funding available in the Renaissance, as well a greater restrictions on entering many fields, making startups more difficult.