2.3. Cloud Concepts and Connectivity

💡 First Principle: Cloud computing shifts infrastructure from capital expense (buying hardware) to operational expense (renting services). The trade-off is control versus convenience—you lose control over underlying infrastructure but gain elasticity, global reach, and reduced maintenance burden.

What breaks without understanding cloud models? Choose IaaS when PaaS would suffice, and you're managing operating systems unnecessarily. Choose public cloud for regulated data without proper controls, and you may violate compliance requirements. Choose private cloud for non-sensitive workloads, and you overspend for control you don't need.

Think of cloud like housing: IaaS is renting land and building your house (maximum control, maximum responsibility). PaaS is renting an apartment (structure provided, you furnish it). SaaS is staying at a hotel (everything provided, you just show up).