Nobody will fault you for confusing the two editors made by Microsoft, seeing as they pretty much have the same name. However, aside from the common name, they have a somewhat different features and functions.
Let's talk about the differents now.
Visual Studio's first version was released in the 1997 year. Visual Studio is Microsoft’s development environment for everything C# and .net. Everyone who wants code with C# and .net should use Visual Studio. In Visual Studio exists (third-party) extensions too. That means in short format: Visual Studio is for C# and .net developers a perfect IDE!
Visual Studio Code first version was released on the April 29, 2015. Visual Studio Code is an open-source rich text editor running on Windows, Linux and macOS. Visual Studio Code is one of the popularest IDEs. Visual Studio Code is perfect for web- and app development but you mightn't find default installed auto completes, code linters but for that are the extensions, you can download in VSCode extensions like in Visual Studio. In short: It's an IDE for everything (focused on web- and app development).
If you're doing Web- and App Development then you should use Visual Studio Code because the most features are focused on these development topics. If you want to code something with C# or .net then you should use Visual Studio.
I made my first article banner on dev.to, how it is?