I have listed the new feature’s available in C# 10. C# 10 has been released in the month of November 2021 and supports .NET 6.0 and Visual Studio 2022 version 17.0.

1) Global and implicit usings
2) Global using directives
3) Implicit usings
4) Combining using features
5) File-scoped namespaces
6) Improvements for lambda expressions and method groups
7) Natural types for lambdas
8) Natural types for method groups
9) Return types for lambdas
10) Attributes on lambdas
11) Improvements to structs
12) Parameterless struct constructors and field initializers
13) record structs
14) sealed modifier on ToString() in record classes
15) with expressions on structs and anonymous types
16) Interpolated string improvements
17) Interpolated string handlers
18) Constant interpolated strings
19) Mix declarations and variables in deconstruction
20) Improved definite assignment
21) Extended property patterns
22) Caller expression attribute

For more detailed features, refer these websites:

1) https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-10
2) https://www.c-sharpcorner.com/article/some-cool-features-in-c-sharp-10/