Finder by default lists directory contents alphabetically regardless of whether it is a file or a folder. This could be confusing for some especially if you're coming from Windows or Linux environment where folder is listed first before files.

Finder can however be configured to list folder first with the following steps;

1. Open Finder preferences from the menu.
   
2. Click on the the Advanced tab.
3. Check the Keep folders on top when sorting by name box.
4. Finder will now lists folders before files.