Task 12 Command Line project question

I have a question regarding the required * in the solution for Task 12 from the Command Line project, please see link below …
https://www.codecademy.com/courses/learn-the-command-line/articles/command-line-offline-project

Task 12 states: List all the files in the asia/ directory and save it in a file, asian_language_files.txt in the todo/ directory. The correct answer is below and I have two questions about it …
Answer: ls asia/* > todo/asian_language_files.txt

My Question: What’s with the asterisk * … why can’t I just input without that *. ls asia outputs all the files in the asia/ directory just fine … so I assumed that I could just input the below, which apparently is a wrong solution because I did not put in the *? …
ls asia/ > todo/asian_language_files.txt