For questions about Entity Framework for .net framework, max. version 6.4, December 2019. Use [entity-framework-core] for current .net (core) versions. Then also please add a version-specific [ef-core-xx] tag.
Entity Framework is .NET's Object-Relational Mapping (ORM) tool that enables .NET developers to work with relational data using domain-specific objects. It eliminates the need for most of the data-access code that developers usually need to write. Either natively, or through third-party libraries, it supports most major RDBM products including SQL Server, MySQL, Oracle, PostgreSQL and SQLite. It also supports Microsoft's "LINQ" syntax and lambda-expressions.
Entity Framework was first developed for .Net framework (production-ready versions 4.x - 6.x). In 2016, Entity Framework for .Net core (EF-core) was introduced, having a completely new codebase which shares many concepts with the classic framework but differs considerably in mapping syntax, query translation and specific features. After version 1 and 2, EF-core 3 came with many breaking changes, marking the beginning of a more stable evolution path. EF core 5 (versions keep track with .Net core versions) has far less breaking changes.
As of version 6.3.0, EF 6 is cross-platform. It targets .Net standard 2.1. NuGet packages are available for .Net core 3 and .NET Framework 4.x.
Because of all these different versions it's very important to use the right tags when asking questions.
Entity Framework is well-documented.
