1) This command starts the command history feature. In this case, the 50 most recent commands will be remembered.
2) A few random commands are entered, which are now being tracked by the history feature
3) History command displays previous commands in a numbered list. In this case, there are five, including the history command itself.
4) A few additional commands are entered
5) With a numeric argument, the history command displays a subset of the list. In this case, the last three commands are listed. Similarly,
history 10 would list the last 10 commands.