Which stage of the SDLC involves evaluating the system to ensure it meets user needs and making necessary adjustments?

The System Development Life Cycle (SDLC) is a sequence of stages a system passes through, from identifying a problem to keeping the finished system useful over time. Each stage has a distinct job: analysis studies the current problem and gathers requirements, design turns those requirements into a blueprint such as diagrams and data structures, and implementation builds and installs the actual system.

After a system has been built and put into use, developers still need to check whether it actually does what users need it to do, and correct any shortfall between what was delivered and what was required. This checking-and-adjusting stage is the review stage. It closes the loop on the whole cycle by comparing the working system against the original requirements and feeding any gaps back for correction.

A common mix-up is treating implementation as the final stage, but implementation only covers building and deploying the system; confirming that it meets user needs happens afterward, at review.