In load testing you would want to subject your software to an equal amount of virtual users as in real production environment. You would then want to monitor the performance under the specified load, usually on a target-test environment identical to the production environment, before going live.
With traditional load testing the cost of building an environment and the priority of load testing versus on-going production tasks, are bringing decision-makers to make compromises and find less adequate solutions to the problem of validating performance under load and throughout time.