src/libraries/Microsoft.Extensions.Logging.Abstractions/README.md
Microsoft.Extensions.Logging.Abstractions provides abstractions of logging. Interfaces defined in this package are implemented by classes in Microsoft.Extensions.Logging and other logging packages.
Commonly Used Types:
Microsoft.Extensions.Logging.ILoggerMicrosoft.Extensions.Logging.ILoggerFactoryMicrosoft.Extensions.Logging.ILogger<TCategoryName>Microsoft.Extensions.Logging.LogLevelMicrosoft.Extensions.Logging.Logger<T>Microsoft.Extensions.Logging.LoggerMessageMicrosoft.Extensions.Logging.Abstractions.NullLoggerDocumentation can be found at https://learn.microsoft.com/dotnet/core/extensions/logging.
The APIs and functionality are mature, but do get extended occasionally.
Microsoft.Extensions.Logging.Abstractions is included in the ASP.NET Core shared framework. The package is deployed as out-of-band (OOB) too and can be referenced into projects directly.