Once you no longer see the drive listed, you can safely disconnect it from your computer. Alternatively, you can select the drive, click on "File" at the top, and choose "Eject".

If you have to use a flash drive on both Macs and Windows PCs, make sure both systems can read it. Here's how to format the drive correctly.

If you are having trouble getting a USB flash drive or external hard drive to mount on your Mac, here are several things you can try to fix the issue.

With Disk Utility, you can also check the free space for any drive you have connected to your Mac from this window, be it a USB flash drive or an external hard drive.

Attach the USB flash drive to your Mac and locate its disk icon on your desktop, in a Finder window, or in the Finder sidebar, then right-click (or Ctrl-click) it and select Encrypt " [USB stick ...

This step by step guide with images covers how to transfer files between iPhone and Mac with a USB flash drive as well as offering a few alternate options.