There are two forms of EU legislation: primary legislation embodied in the treaties, and secondary legislation in the form of regulations, directives and decisions which are used to implement the policies set out in the treaties.
The treaties are the basis of the European Union - legal agreements between the member states. They are the EU's primary legislative texts, setting out the aims of the Union and establishing the structures, powers and processes through which it can pursue them.
The main text of a treaty may be supplemented by protocols and declarations: a protocol is legally binding on the member states to which it applies; a declaration has no legal force.
Location of printed treaties: Classmark QZ1
You can read the Treaties online in the legislation area of the EU website
Secondary legislation is created by the institutions and forms the working basis of community law. It includes regulations, directives, decisions, recommendations and opinions.
Definitions of the main instruments of secondary legislation, according to Article 249 of the Treaty of Rome (EC Treaty):
Secondary legislation is available on the Eurlex database, and also on Westlaw and LexisLibrary.