Cloud computing is a technology that allows users to access and use computing resources (such as servers, storage, databases, networking, software) over the internet, without needing to own or manage physical infrastructure. It revolutionizes data storage and accessibility by providing several key benefits:

1. **Scalability:** Cloud services allow users to scale their resources up or down based on demand, providing flexibility and cost efficiency.

2. **Accessibility:** Users can access their data and applications from anywhere with an internet connection, promoting collaboration and remote work.

3. **Cost-Efficiency:** Cloud computing eliminates the need for organizations to invest in and maintain their own infrastructure. Users pay for what they use, shifting from a capital expense model to an operational expense model.

4. **Reliability:** Cloud service providers often offer high levels of reliability through redundant data storage and backup systems, reducing the risk of data loss.

5. **Security:** Cloud providers invest heavily in security measures, often surpassing the capabilities of individual organizations. However, data security and compliance remain shared responsibilities between the provider and the user.

Overall, cloud computing has transformed how data is stored, processed, and accessed, offering a more flexible, cost-effective, and scalable solution compared to traditional on-premises infrastructure.