Understanding the Cloud and Web Services Landscape

The cloud services landscape is often explained as a stack: Infrastructure as a Service (raw compute and storage) at the bottom, Platform as a Service (managed runtimes) in the middle, and Software as a Service (ready-to-use applications) at the top. Each layer trades control for convenience relative to the one below it.

Alongside that stack sit specialized services that cut across it — content delivery networks that cache content close to users, managed databases that remove the operational burden of running one yourself, and managed hosting that combines infrastructure with hands-on support.

Most real businesses end up using a mix of these rather than picking one layer exclusively: a managed database here, a CDN there, and application hosting somewhere in between. Understanding the landscape is mostly about knowing which layer solves which specific problem.