A string is a finite sequence of symbols, commonly used for text, though sometimes for arbitrary data.

Windows Presentation Foundation, or WPF, is a subsystem for rendering user interfaces in Windows-based applications.

MongoDB is a scalable, high-performance, open source, document-oriented NoSQL database. It supports a large number of languages and application development platforms. Questions about server administration can be asked on https://dba.stackexchange.com.

Writing software specific to the Microsoft Windows operating system: APIs, behaviors, etc. GENERAL WINDOWS SUPPORT IS OFF-TOPIC. Support questions may be asked on https://superuser.com

PostgreSQL is an open-source, relational database management system (RDBMS) available for all major platforms including Linux, UNIX, Windows and OS X. Mention your version of Postgres when asking questions. Consider dba.stackexchange.com for questions concerning administration or advanced features.

Xcode is Apple's integrated development environment (IDE). USAGE NOTE: Use this tag only for questions about the Xcode IDE itself, and not for general Mac or iOS programming topics. Use [cocoa] for Mac programming questions, and [cocoa-touch] or [iOS] or [Swift] for iOS programming questions.

This tag is for questions about scripts written for the Bash command shell. For shell scripts with syntax or other errors, please check them at https://shellcheck.net before posting here. Questions about interactive use of Bash are more likely to be on-topic on Super User than on Stack Overflow.

Oracle Database is a Multi-Model Database Management System created by Oracle Corporation. Do NOT use this tag for other products owned by Oracle, such as Java and MySQL.

Git is an open-source distributed version control system (DVCS). Use this tag for questions related to Git usage and workflows. DO NOT USE the [github] tag for Git-related issues simply because a repository happens to be hosted on GitHub. Also, do not use this tag for general programming questions that happen to involve a Git repository.

Visual Basic.NET (VB.NET) is a multi-paradigm, managed, type-safe, object-oriented computer programming language. Along with C# and F#, it is one of the main languages targeting the .NET Framework. VB.NET can be viewed as an evolution of Microsoft's Visual Basic 6 (VB6) but implemented on the Microsoft .NET Framework. DO NOT USE this tag for VB6, VBA or VBScript questions.

Amazon Web Services (AWS) is a public-cloud: IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (Software as a Service) provided by Amazon. Questions about programming and architecture are on topic. General server help can be obtained at https://serverfault.com. The AWS tag is rarely used alone and will usually be used with other tags to more clearly define the topic of the question.