Basically, the two systems differ from Magento in that Magento Open Source is free of charge, while Magento Commerce (formerly Magento Enterprise) is fee-based but, therefore offers more possibilities. For many small agencies and start-ups, Magento Open Source is the perfect shop system, since costs are only incurred for hosting and additional special extensions. For larger companies, who often choose Magento Commerce (Enterprise), there are additional licence costs depending on the size of the installations and the turnover of the company.
Magento Commerce offers additional features, such as B2B modules, tools for customer retention, etc. - but many of the functions can also be realised by external services or modules using the open source system. Our experts can advise you here on how your requirements can be implemented most efficiently and which Magento version is the right solution for you.