Regarding this, why can't I use my Seagate on Mac?
One of the reasons you can't add files to a Seagate hard drive on your Mac is that it's formatted with NTFS. On macOS, you can only read disks in this format, not write to them. This will prevent you from adding, changing, or deleting files. Fortunately, Seagate offers the Paragon Driver for macOS.
Additionally, can I plug my external hard drive into a Mac? External hard drives, thumb drives, USB drives, Flash memory cards, and devices like iPod are examples of storage devices that you can connect to your Mac using Thunderbolt, USB, or FireWire cables, or connect wirelessly using Bluetooth. If your Mac has a USB-C port, see About USB-C.
Secondly, is Seagate good for Mac?
The Seagate Slim for Mac is a good, mainstream portable drive for iMacs and MacBooks. It fits easily in a pocket and comes with USB 3.0 so it will work fine with your recent vintage MacBook Air. PCMag editors select and review products independently.
How do I know if my Mac has a Seagate external hard drive?
Open Finder > Applications > Utilities > Disk Utility
If the drive is not detected in Disk Utility then see the System Information/System Profiler section. If you are using macOS 10.13 or higher then click view in the upper left and select “Show All Devices” which allows you to see both the disk as well as volumes.
