You can easily share multiple images via iMessage, MMS, or email, or uploaded to locations like Facebook and Flickr. In the Photos app, navigate to the Photos tab or any album in the Albums tab and press Select to choose your images.
If sending via email, be careful not to select too many at once, as some email providers have a size limit on attachments. No more than five at a time is a good rule of thumb.
Once happy with your choice, tap the Share icon (a square with an upward arrow in it) and pick one of the available options. On the top row, you’ll see sharing suggestions. To share your photos to an app like Mail or Facebook Messenger, choose an option from the middle row.