A screenshot tells thousand words:

Reference: Comparing WSL Versions https://learn.microsoft.com/en-us/windows/w...ompare-versions
In short, WSL2 is full Linux kernel, others are same as WSL1. I heard that WSL2 supports GUI app, but I got "Segmentation fault" error when running my own Linux GUI program.
This is how I follow the online tutorial to convert from WSL1 to WSL2:
Start PowerShell and Run as Administrator:
CODE
Enable-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform

After that need to restart PC....
Then download and install wsl_update_x64.msi ( https://wslstorestorage.blob.core.windows.n..._update_x64.msi )
Finally type:
CODE
wsl --set-default-version 2
CODE
wsl --set-version Ubuntu-22.04 2
....where Ubuntu-22.04.2 may vary depending on what you see on:
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C:\WINDOWS\system32>wsl --list --verbose
NAME STATE VERSION
* Ubuntu-22.04 Stopped 2