https://www.mudassiriqbal.net/project-management-terms-and-concepts There are many concepts and definitions which require special attention by all PMP Aspirants as the terminologies are largely used interchangeably in the real world.

1. Resource Leveling and Resource Smoothing
These resource optimizing techniques are available as scheduling tools to Project Manager to
effectively create a viable schedule during Develop Schedule Planning Process of Project Schedule
Management
The official version from PMBOK Ver 6.
ResourceLeveling: A techniquein which start and finish dates are adjusted based on
resource constraints with the goal of balancing demand for resources with the
available supply
ResourceSmoothing:A techniquethatadjuststheactivities of a schedule model such
that the requirements for resources on the project do not exceed certain predefined
resource limits
Resource Leveling
Resource levelling in project management is defined as a technique used in which the start and end
dates are regulated depending on resource limitations. It aims to balance demand for sources within
the available supply. While using specifically designed project software, levelling often means
undertaking conflicts over allocations in the project plan by letting the software to measure delays
and update tasks automatically.
In Resource Leveling, a critical path is a commonly used technique by project managers. It represents
both the longest and shortest time interval paths in the network diagram to complete the project.
While using this technique focus is on Resource scarcity.

2. https://www.praxisframework.org/en/library/resource-limited-scheduling
Resource Smoothing
Resource smoothing is among the important project management tools used in resource optimization
techniques. The procedure adjusts the practices of a schedule model to ensure all requirements for the
resources doesn’t go beyond the resource limitations as pre-defined during the planning phase.
Resource smoothing is used to settle certain resources and time but with a diverse approach than
resource levelling. It aims to finish the project or activity in a given time period while preventing any
unnecessary resource demands. Time is an important constraint here and therefore no activity can be
delayed more than their float.
Resource Smoothing deals with time-constrained resource scheduling i.e Optimize the
resources, largely non-critical resources with the mandatory, hard or external constraint
on time which cannot be breached
Resource Levelling deals with resource-constrained scheduling i.e Limited resource
availability with little or no time constraint
Comparison
 Resource Levelling may impact your critical path whereas Resource Smoothing doesn’t.
 Resource Smoothing is performed after resource levelling to eliminate the peaks and troughs
from the schedule

3.  Resource levelling balance the resource demands by levelling the under and overallocated critical
resources.
 Resource smoothing makes sure that resources are evenly allocated