Google Drive vs ICloud

Google Drive
Online file storage and syncing service working as a file system for other Google's services. Allows to sync files between all your computers and mobile devices or collaborate on files with your team and partners. Version control, OCR, powerful online viewer. Provides 5 GB free disk space. Google Drive free alternatives are: OneDrive, Box, Dropbox
iCloud is cloud service done right. It stores your music, photos, apps, calendars, documents, and more. And wirelessly pushes them to all your devices.
Face to face in the news:

2013 - Apple launches iWork for iCloud to catch up with Google Drive

Historically Apple doesn't like to build business applications, but Office - is still an important part of the platform and competitors (Microsoft and Google) got far ahead in this aspect. So Apple decided to fix, perhaps, the main drawback of its office suite - the absence of online version. In June, at the WWDC conference Apple officially introduced iWork for iCloud and now the online apps Pages, Numbers and Keynote are available to all in the iCloud online accounts (in beta). However, at the moment, these editors can only bring a smile for MS Office and Google Docs users. For example, the text editor Pages even doesn't allow to add tables and spell check works only in English. There are no collaboration tools. But the good news is that you can upload and edit MS Word, Excel, PowerPoint documents (and formatting sometimes isn't corrupted) and download documents in MS Office formats and PDF.