how can i know ubuntu version

To find out which version of Ubuntu you are running, you can either use the GUI by navigating to Settings and then About, or the command line by opening a terminal and using the lsb_release -a command. 

Here’s a more detailed explanation:

Using the GUI:

1. Open the Settings application.
2. Go to “Details” on the left menu bar.
3. The Ubuntu version will be displayed in large text below the Ubuntu logo. 

Using the Command Line:

1. Open a terminal (Ctrl+Alt+T).
2. Type lsb_release -a and press Enter.
3. The output will include the Ubuntu version on the “Description:” line. 

Other Methods:

• cat /etc/issue: This command will print the version information in a single line. 
• cat /etc/lsb-release: This command will print the contents of the lsb-release file, which also contains version information. 
• hostnamectl: This command provides various system information, including the Ubuntu version.