Second-generation programming language (2GL) is a generational way to categorize assembly languages. The term was coined to provide a distinction from higher level third-generation programming languages (3GL) such as COBOL and earlier machine code languages. Second-generation programming languages have the following properties:

• The code can be read and written by a programmer. To run on a computer it must be converted into a machine readable form, a process called assembly.
• The language is specific to a particular processor family and environment.