Cloud files refer to digital content stored remotely on internet servers rather than on local device storage. Opening them on mobile devices is possible using dedicated mobile applications provided by cloud storage services or compatible third-party software. These apps connect over the internet or a mobile network to the cloud servers, download the requested file, and typically use the mobile device's built-in viewers or integrated app capabilities to display the content. This process allows access to files from anywhere without needing them physically stored on the phone itself.

Common examples include using the Dropbox mobile app to open PDF reports while travelling or accessing a shared Google Sheets file via the Google Drive app to update sales figures during a client meeting. Industries from healthcare to construction utilize this capability; medical professionals review patient scans via HIPAA-compliant cloud storage apps on tablets, while engineers access blueprints stored in Box or OneDrive directly on job-site iPads.

Advantages include universal access and reduced need for device storage space. Key limitations involve dependence on a reliable internet connection and potential security vulnerabilities when using public Wi-Fi. Leading cloud providers mitigate security risks through robust encryption and multi-factor authentication. Future advancements focus on enhancing offline access features and deeper mobile operating system integration, making cloud files increasingly seamless to open and edit on smartphones and tablets.