Cloud infrastructure is the collection of cloud resources used to build and run applications. It includes virtual servers, storage, networking, databases, security, and monitoring services provided by a cloud platform.
With cloud infrastructure, you can create applications without buying physical hardware. Services like Amazon EC2, Amazon VPC, Amazon S3, Amazon RDS, and IAM work together to provide a complete cloud environment.
In simple words, cloud infrastructure is the foundation of cloud computing. It provides all the resources needed to build, deploy, secure, and manage applications in the cloud.