If you don't yet have iCloud Photo Library enabled on your iPhone or iPad, you can use iTunes to sync your Mac or PC's images to your iPhone.
Prefer iTunes syncing to iCloud? No problem. It's a piece of cake to get your images from Photos — or old versions of iPhoto or Aperture — to your iPhone or iPad, and you've got plenty of options for what you'd like to sync: albums, events (dates), and faces, or individually choose a combination of albums, events, and faces that you want to sync.
- Organize your photos accordingly in iPhoto, Photos, or Aperture.
- Plug your iPad or iPhone into to your Mac.
- Launch iTunes, if it doesn't open automatically.
- Click on the iOS device icon in the top bar, then click the Photos tab.
- Click the checkbox next to Sync Photos.
- Click iPhoto, Photos, or Aperture from the "Copy photos from" drop-down menu.
- Click the options you prefer.
- Click Sync in the bottom right corner.
Your iOS device will copy over all the images you've selected.