iCloud and iMessage

>>> Messages in iCloud doesn’t just keep your messages in sync across your devices. It also stores your entire message history in iCloud, including any photos or file attachments — so if you’re running low on storage space it’s a good idea to go into Settings > iCloud > iCloud Storage and have a clear–out from time to time: if you’re an avid Messages user, your months of reaction GIFs and cat videos can end up using a lot of your iCloud storage.