We should learn Kotlin Programming Language Basic terminology at the beginning.

  • A program is a sequence of instructions (called statements), which are executed one after another in a predictable manner. Sequential flow is the most common and straightforward situation when statements are executed in the order they are written, i.e., from top to bottom, one after another;
  • A statement (or a programming statement) is a single command to be executed (like printing a text);
  • An expression is a piece of code that produces a single value (for example, 2*2 is an expression);
  • A block is a group of zero or more statements enclosed in a pair of curly braces {...}; our program consists of a single block;
  • A keyword is a word that has a special meaning in the programming language. Names of keywords can’t be changed;
  • An identifier (or a name) is a word written by the programmer to identify something;
  • A comment is a piece of text that is ignored when executing the program – it just explains a part of the code. Comments start with //;
  • Whitespace is a blank area, a tab, or a newline; it is used to separate words in the program and to improve readability.

Credit: https://hyperskill.org/