Linux Command Learning Series#4: How to Find Out Ubuntu Version: 6 Methods
Usually, if you are well-known about the Ubuntu release cycle, you probably know what Ubuntu desktop or server version you are running in your system. Generally, there are two Ubuntu versions per year and one LTS (long-term support) version every two years.
Having said that, it's always a good idea to check what version you are running for development projects and compatibilities. Here's how to find the Ubuntu version.