What is the difference between “compile time” and “run time”?

Question

I do not understand what is meant by the terms \"compile time\" and \"run time\" (or \"runtime\").

I\'m also a bit confused about what \"value type\" and \"reference ty

Answer 1

A variable that is a value type, stores the data, while a variable of a reference type stores a reference to the data.

In computer science, compile time refers to either the operations performed by a compiler (the "compile-time operations"), programming language requirements that must be met by source code for it to be successfully compiled (the "compile-time requirements"), or properties of the program that can be reasoned about at compile time.

The operations performed at compile time usually include syntax analysis, various kinds of semantic analysis (e.g., type checks and instantiation of template) and code generation.

In computer science, the qualifier run time, run-time, runtime, or execution time refers to the period while a computer program is actually executed ("run") in a computer, from beginning to termination. It may also mean the program's running time, the duration of that period.