AI IaaS is on-demand, cloud-based access to GPUs, networking, and storage; you rent the capacity you need by the hour or second instead of buying and operating the hardware yourself. The tradeoff is the same one cloud computing has always offered: building your own data center gives you full control and, at very high sustained utilization, a lower per-hour cost, but it requires upfront capital, lead time to provision, and an ops team to keep it running. AI IaaS platforms like Runpod let you start serving traffic in minutes, scale to zero when there's no demand, and avoid being locked into hardware that ages out as new GPU generations ship.