Jun 30, 2019 12:00 AM
Replying to Eric Isom
...
"Validate Scope is the process of formalizing acceptance of the completed project deliverables."
"Control Scope is the process of monitoring the status of the project and product scope and managing changes to the scope baseline."
PMBOK® Guide, pp. 163, 167
Validate Scope is meeting with the customer and getting sign off on the project deliverables.
Control Scope is the work you do throughout the project to keep an eye on scope, including managing any changes to the scope.
Closely related is the Control Quality process, which measures whether the project deliverables meet the quality requirements. This should be done before you Validate Scope with the customer, and is an important input to the Validate Scope process.