The single market is built around four basic freedoms: the freedom of movement of goods, the freedom of movement of services, the freedom of movement of capital, and the freedom of movement of people. This means that goods, services, capital and people can move freely between EU member states without tariffs, customs duties, or other trade barriers.

This facilitates cross-border trade and investment, which can lead to increased competition, lower prices, and greater choice for consumers and businesses. It also allows for increased labour mobility, which can help to boost economic growth and productivity.

The single market is based on a set of common EU rules and regulations, which are designed to ensure fair competition and protect the rights of consumers and workers. These rules are intended to create a level playing field for all businesses operating in the EU, regardless of where they are located.

Additionally, the EU's Single Market also includes Customs Union, where all member states agree to impose common tariffs on imports from outside of the EU, and thus create a barrier free trade between member countries with no tariffs.