Cloud computing is the on demand delivery of computing resources over the internet, priced on usage rather than large upfront purchases. Instead of buying and maintaining servers and data centres, an organisation rents what it needs from a provider and scales capacity up or down in minutes. These resources include virtual machines, containers, storage, databases, networking, identity services, analytics and security tools, all reachable through a web console or APIs. The provider runs the physical sites, power, cooling and hardware replacement, while customers focus on deploying applications and data.
Several features define the cloud model. It offers self service so teams can provision what they need without waiting for manual tickets. It is accessible over standard networks from almost anywhere. Resources are pooled across many customers, which improves utilisation and keeps costs competitive. Capacity is elastic so systems can expand for a peak and contract afterwards. Usage is metered, so you pay for what you consume and can track costs by project or team.
Service models describe how much of the stack you outsource. Infrastructure as a Service supplies virtual machines, block and object storage and software defined networking, giving you control of operating systems and middleware. Platform as a Service provides managed runtimes, web and application services and databases so developers deploy code without managing servers. Software as a Service delivers complete applications through a browser with the provider handling updates and availability.
Deployment models describe where workloads run. Public cloud serves many customers from shared infrastructure. Private cloud dedicates capacity to one organisation, either on premises or hosted. Hybrid cloud links private environments with public services so workloads and data can move between them. Many organisations also use more than one public cloud to match features, price or regional coverage.
Cloud changes roles and responsibilities. Providers secure the facilities and core platform, while customers configure identity and access, patch operating systems and applications when they control them, and protect their own data. Good practice includes clear access policies, encryption, backups, cost monitoring and automated deployment pipelines.
Typical uses range from hosting websites and business systems to running analytics, machine learning experiments, disaster recovery, test environments and global content delivery. The benefits are speed, scalability and alignment of cost with demand. The trade offs include potential vendor lock in, the need for disciplined cost control and careful attention to data location and compliance. When planned well, cloud computing gives organisations a flexible foundation to build, secure and grow digital services.