"An assembly is the unit of deployment and versioning in the .NET Framework. An assembly contains a manifest, metadata, MSIL, and possibly binary resources. Most assemblies are single files, but an assembly can consist of multiple files, such as DLLs, picture files, and even HTML files." (Adam Nathan, ".NET and COM: The Complete Interoperability Guide", 2002)
"The unit of deployment and versioning in the .NET Framework. It establishes the namespace for resolving requests for types and determines which types and resources are exposed externally and which are accessible only from within the assembly. An assembly includes an assembly manifest that describes the assembly's contents." (Damien Watkins et al, "Programming in the .NET Environment", 2002)
"A managed application module that contains class metadata and managed code as an object in SQL Server. By referencing an assembly, CLR functions, CLR stored procedures, CLR triggers, user-defined aggregates, and user-defined types can be created in SQL Server." (Thomas Moore, "MCTS 70-431: Implementing and Maintaining Microsoft SQL Server 2005", 2006)
"A managed application module, composed of class metadata and managed code, that can be embedded in a database solution as a database object in SQL Server 2005." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)
"Application logic that is stored in, and managed by, the SQL Server database server, including objects like triggers, CLR software, and stored procedures. Assemblies are written in a .NET language, such a C# or Visual Basic." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)
"In SQL Server, a .NET assembly is a compiled SQL CLR executable or DLL." (Michael Coles, "Pro T-SQL 2008 Programmer's Guide", 2008)
"A managed application module that contains class metadata and managed code." (Jim Joseph et al, "Microsoft® SQL Server™ 2008 Reporting Services Unleashed", 2009)
"In .NET applications, the smallest self-contained unit of compiled code. An assembly can be a complete application, or a library that can be called by other applications." (Rod Stephens, "Start Here!™ Fundamentals of Microsoft® .NET Programming", 2011)
"The smallest independent unit of compiled code. Typically, this is a Dynamic Link Library (DLL) or executable program." (Rod Stephens, "Stephens' Visual Basic® Programming 24-Hour Trainer", 2011)
"A managed application module containing class metadata and managed code as an object in SQL Server, against which CLR functions, stored procedures, triggers, user-defined aggregates, and user-defined types can be created in SQL Server." (Microsoft, "SQL Server 2012 Glossary", 2012)
"In SQL Server, a .NET assembly is a compiled SQL CLR executable or DLL." (Jay Natarajan et al, "Pro T-SQL 2012 Programmer's Guide" 3rd Ed., 2012)
"The fundamental logical unit of managed code, consisting of one or more files containing Common Intermediate Language instructions and metadata. See also CIL." (Mark Rhodes-Ousley, "Information Security: The Complete Reference" 2nd Ed., 2013)
