how to transfer photos and videos from icloud to external hard drive

Hello ntnylions91,

We would advise starting out by downloading the content you want to transfer to your computer, then you can move it to the external drive. This article offers more information on that process: Download iCloud photos and videos - Apple Support. Follow this guidance:

"How to download photos and videos from iCloud.com

If you want to save copies of your photos and videos from iCloud.com to your iPhone, iPad, iPod touch, or your Mac or PC, follow these steps.

On your iPhone, iPad, or iPod touch

1. On iCloud.com, tap Photos. 
2. Tap Select, then tap a photo or video. To select multiple photos or videos, tap more than one. To select your entire library, tap Select All.
3. Tap the more button  .
4. Choose Download, then tap Download to confirm. 

If your photos download as a ZIP archive, learn how to uncompress the folder on your iPhone, iPad, or iPod touch. 

On your Mac or PC

1. On iCloud.com, click Photos and select a photo or video. Hold the command key on your Mac or control key on your PC to select multiple photos or videos. 
2. Click and hold the download button  in the upper corner of the window. If you want to download your photo or video as it was originally captured or imported, choose Unmodified Original. For JPEG or H.264 format — including edits, and even if it was originally in HEIF or HEVC format — choose Most Compatible.*
3. Click Download.

If your photos download as a ZIP archive, learn how to uncompress the folder on your Mac or your PC. 

What happens when you delete photos or videos

Remember, when you delete a photo from iCloud Photos, it also deletes from iCloud and any other device where you're signed in with the same Apple ID — even if you turned on Download and Keep Originals or Download Originals to this Mac. If you choose to download your originals, this also impacts your device storage. Learn more about how to manage your device storage. You can also learn how to AirDrop your photos and videos to another device."

We hope this helps. Let us know if we can assist with anything else at all. Take care.

You have to transfer videos from iPhone to a browser Transfer photos and videos from your iPhone or iPad to your Mac or PC - Apple Support

Photos can’t be transferred directly from iCloud to an external hard drive for that you need to set up iCloud photo library see the article Set up and use iCloud Photos - Apple 

And its preferences Change preferences in Photos on Mac - Apple  open finder > Go > home > your user name > pictures either drag and drop Photos Library.photoslibrary to an external hard drive , the second method is right click on Photos Library.photoslibrary and click on show package contents in the upcoming column , you can also drag and drop complete masters folder to an external hard drive that is connected .

Also as per the article Back up the library in Photos on Mac - Apple 

Manually copy your library to an external storage device: Drag the Photos library (by default in the Pictures folder on your Mac) to your storage device to create a copy.See this article also

Photos library - Move your Library to an external storage device

Note : your profile shows using an iPhone see Connect external storage devices to iPhone - Apple Support