C# (pronounced "see sharp") is a high level, statically typed, multi-paradigm programming language developed by Microsoft.
PHP(Hypertext Preprocessor) is a widely used, high-level, dynamic, object-oriented, and interpreted scripting language primarily designed for server-side web development.
Android is Google's mobile operating system, used for programming or developing digital devices (Smartphones, Tablets, Automobiles, TVs, Wear, Glass, IoT).
HTML (HyperText Markup Language) is the markup language for creating web pages and other information to be displayed in a web browser.
CSS (Cascading Style Sheets) is a representation style sheet language used for describing the look and formatting of HTML (HyperText Markup Language), XML (Extensible Markup Language) documents and SVG elements including (but not limited to) colors, layout, fonts, and animations.