Vscodium is an open-source project based on Visual Studio Code by Microsoft. It's essentially a clone of VSCode, but with a key difference: VSCodium removes all telemetry code. This means it doesn't collect any usage data and send it back to Microsoft.

The big difference is regarding the Telemetry Sends usage data to Microsoft, "helping the company improve the product and identify issues."
In really it track your preferences, time usage, .env files, all to Microsoft.

Alternatively VSCodium has No telemetry Does not collect or send usage data.

Greater privacy for users who are concerned about data collection.

The extensions that you use on VSCODE will work normally on VsCodium.
For more info itsfoss.com/vscodium

Stay free from big techs, also pay attention in the Copilot assistance, has huge discussion, the collect your files like .env, preferences etc.

Imagine that it can be collect sensitive data, like your business core from your project. COMPLICATED! pay attention.