Before you can share any kind of photo album, you first have to make sure you've turned on the shared albums feature via iCloud Photo Sharing. here's how:
Tap Settings.
Tap Photos.
Move the Shared Albums slider to on/green.
How to Share an Existing Album on iPhone
If you've already got an album full of share-worthy photos, follow these steps to share an album with up to 100 of your closest friends:
Go to Photos.
Select the Albums tab and tap the album you want to share.
Tap ...
Tap Share Photos.
Tap Add to Shared Album.
Tap Shared Album.
Tap New Shared Album (even though the album already exists on your iPhone, you have to create a shared album for others to see it).
Type a name for the share album and tap Next.
Enter the names, email addresses, or phone numbers of the people you want to share the album with. If they're in your Contacts app, they'll appear in a tappable drop-down list. Other iPhone users will be in blue.
Just like with iMessage, non-Apple users appear in green. They can access a shared library even without the Photos app.
Enter as many names as you want to share with and tap Next.
Tap Post to share the photos and the album.
Once you've created or shared an album, it appears in the Photos app in the Shared Albums section. To control the album's settings, tap it and then tap the person icon at the top. There, you can add or remove people from the album, allow people to add their own photos (move the Subscribers Can Post slider to on/green), get notifications of activity in the album, make the album public, and delete the album.
How to Create a Shared Album on iPhone
If you have a set of photos but haven't compiled them into an album yet, you can do that before you share the album with others. Here's what to do:
Tap Photos.
Tap +.
Tap New Shared Album.
Give the album a name and tap Next.
Enter the names, email addresses, or phone numbers of the people you want to share the album with. If they're in your Contacts app, they'll appear in a tappable drop-down list. Other iPhone users will be in blue.
Just like with iMessage, non-Apple users appear in green. They can access a shared library even without the Photos app.
When you're done, tap Next > Create.
Tap the album you just created.
Tap +.
Browse all of your existing photos. Tap each photo you want to add to the new shared album.
When you've tapped all of the photos you want to add to the new album, tap Add.
Add a note that will be sent to the people you're sharing the album with, if you want, and tap Post.
The shared album is created and you can see the photos in it, and add to or remove them. To control the settings for the album, check out the tips in the callout above.
How to Accept a Shared Album Invite on iPhone
FAQ
What is the difference between albums and folders in iPhone Photos?
In the iPhone Photos app, your photos are contained in albums, and those albums are contained in folders. Using folders makes it easier to keep your albums organized.
How do I delete an album in iPhone Photos?
To delete an album in iPhone Photos, tap Albums > See All > Edit. Tap the red minus sign (-) above the album you want to delete. When you're finished, tap Done.
Why can't I share an album on iPhone?
Tap Settings > [your name] > iCloud > Photos. Turn on Shared Albums. Go back to the Home screen.How do I share one of my albums with someone?
Create a shared album.On your mobile device, open the Google Photos app ..Sign in to your Google Account..At the bottom, tap Photos..Select photos or videos for the album..At the top, tap Add ..Tap Shared album..Enter an album title..When the album is complete, tap Share..How do I invite someone to a shared album on my iPhone?
Under "Library," tap Shared Library. Tap Add Participants. Input the name of the person(s) you'd like to invite, then select their email address or number from the search of your contacts list. Tap the encircled + button if you want to add more people.