What is the difference between scope creep and out of scope ? How is scope creep implemented during project without change request?
The term "out of scope" refers to all functionality that is not part of the scope of the project as it was agreed upon at the start of the project and as it has been amended by change requests. The term can additionally be used for work that does not contribute to achieving the functionality that is within the scope of the project.
Scope creep refers to the process of adding functionality that is out of scope without going through the agreed upon change process to extend the project's scope.
When (attempts at) scope creep occur from stakeholders, they usually take the form of statements along the line of "I know this is what we agreed upon, but I really meant that X was included as well." Depending on your relations with the stakeholder and the amount of effort that goes into X, you can either expand the scope silently (accept the scope creep), or enforce the proper change procedures to get the change officially within scope (and with the appropriate budget and time for it).