The using System line means that you are using the System library in your project.

This feature of the IDE attempts to sense what you are going to type before you type it.

This escape sequence advances the next line; similar to pressing the Enter Key.

This escape sequence advances to the next horizontal tab stop.

This type of application that can be developed in C# normally sends request to the OS to display text on the command console or to retrieve data from the keyboard.

This type of application that can be developed in C# are designed for desktop use and for a single platform. It runs on PC desktops IDE of Visual Studio.

This application is used to quickly build applications that run on the Web for end users, to view through browser-neutral interface (UI's)

This format is used to indicate the position of the variable in the string. This is also called format specifier.

This command in CMD means "change directory or folder"