Which financial model describes paying monthly for computing usage instead of making large upfront purchases?

Operational expenditure (OpEx) describes spending money on services or products that are consumed over time, like cloud computing. You pay for what you use, typically on a monthly basis, without large upfront investments. This aligns perfectly with the pay-as-you-go model of cloud services. Capital expenditure (CapEx) involves large, upfront investments in physical infrastructure that depreciates over time. Reserved pricing is a specific billing option within cloud computing that offers discounts for committing to a certain usage level, but it's still a form of operational expenditure. A fixed-cost model implies a consistent, unchanging payment regardless of usage, which doesn't accurately represent the variable nature of most cloud computing consumption.