In simple terms, scheduling is to list a set of activities/tasks (activities/tasks description) in the right order (logical sequence) you plan to accomplish them, within a specific timeframe (estimated activity durations) and what is going to be required (resources) to get the job done.
Relationships between the activities/tasks will be established in order to be completed in the most efficient matter.
In project management, developing a project schedule, would you to accomplish the following:
a) understand the defined scope of work
b) Develop the project Work Breakdown Structure (WBS)
c) Define the list of activities and their sequence.
d) To estimate the activity durations we need to know/list who is going to do the work, how much they can do per hour or per day and quantities of material etc.
e) Develop a detailed project schedule network diagrams that will serve as a plan to complete the work using one of the well-known project management software available.
f) Work the plan (schedule)
The approved schedule would be used as a tool to monitor the progress and control the project objectives.