What are the main aspects of the definition of planning?

The main aspects of the definition of planning are mentioned below:

a. Planning is deciding in advance what to do and how to do.

b. It involves the setting up of objectives and choosing the best alternative from the various alternative.

c. It reduces the gap between where are we and where we want to reach.

d. It is a basic managerial function.

e. Plans are devised by the top management.

f. Plans are formulated for a fixed duration of time