System searches, like those in your computer's file explorer (e.g., Finder on macOS, File Explorer on Windows), primarily index and search files stored locally on your device's hard drive. Cloud storage services like iCloud Drive and Google Drive store your files on remote servers. Your operating system's native search engine is designed for speed and efficiency on local files it controls directly; it does not have the built-in capability or permission to constantly index or search the vast, secure data held remotely in your cloud accounts. Searching cloud data requires specific connectivity and authentication.

For instance, if you store a document solely in Google Drive and try to find it using Windows File Explorer's search bar, it won't appear in the results because that search operates locally. To find that file, you must use the Google Drive website, the Google Drive for desktop app interface, or a search within a dedicated cloud app like Apple's Files app (for iCloud). Some tools like Spotlight (macOS) can find file names from cloud apps if they are installed and synced locally, but they still cannot deeply search content stored solely online without prior syncing.

The main advantage is enhanced privacy and security – your cloud data isn't constantly accessed or indexed by the OS without specific permission. However, this creates a fragmented search experience for users. You must know which files are local versus cloud-only and use separate search tools. Future developments aim for better integration, such as deeper linking between system search and cloud provider apps, or initiatives like the iOS Files app allowing some cross-provider searches, but universal system-level content search across all cloud services remains unlikely due to technical, security, and proprietary barriers.