Articles 101 and 102 TFEU refer to the notion of undertaking without defining it. According to case law, an undertaking is characterized by its economic autonomy: an entity is an undertaking under Article 101 of the Treaty when it carries out an economic activity and operates independently on the market. No legal form in theory excludes the classification as an undertaking: only the non-economic nature of certain activities of a body is likely to exempt it from the scope of application of competition law. This is the case of social security organizations where their object is not economic but fulfills an exclusively social function based on the principle of national solidarity and is entirely non-profit-making, with benefits paid being statutory benefits and bearing no relation to the amount of the contributions. However, a non-profit-making organization managing an old-age pension system designed to top up the basic compulsory scheme, or a pension fund, which itself determines the amount of the contributions and benefits and operates in accordance with the principle of capitalization, is an undertaking within the meaning of competition law.