Question: when I type ls or clear...
“command is not recognized as an internal or external command, operable program or batch file”
[enter image description here](https://i.stack.imgur.com/dYzj8.png)

Answer: 
`ls` and `clear`, are Linux commands, not Windows.
Use `dir` and `cls` commands in Windows.

Or use Git Bash (which comes along with Git Installation) to use linux commands like `clear` and `ls`