[linux] How do I copy folder with files to another folder in Unix/Linux?

The option you're looking for is -R.

cp -R path_to_source path_to_destination/

• If destination doesn't exist, it will be created.
• -R means copy directories recursively. You can also use -r since it's case-insensitive.
• Note the nuances with adding the trailing / as per @muni764's comment.