MSTest has long shipped with Visual Studio. There are a few other options when it comes to testing frameworks for C# and .NET. Many of these frameworks have feature parity and differ only slightly in their choices of attributes, assertions, and exception handling. Among the top contenders for testing frameworks is xUnit. Many developers actually prefer this to MSTest and would argue that it is more feature-rich and has stronger community support. Arguments aside, we'll be using xUnit for our C# and .NET tests from here on out.
Feel free to stick with MSTest if you prefer. Just know that you'll need to account for the semantic differences (such as TestMethod vs Fact) and slight differences in functionality.