What is the definition of psychosocial task?

When we think of psychosocial
development and psychosocial tasks, we usually think of
Erikson and his stages of psychosocial development.

In this
theory, human development is defined as going through 8 stages from infancy until
adulthood.  The psychosocial tasks are the developmental
markers that define each stage.  They are social and physical challenges that the person
is able accomplish, thereby marking which stage he or she has mastered, and which he or
she is in at any given point in life.

For example, in the
infancy stage, the only psychosocial task the baby is expected to master is to learn
whether caregivers actually provide basic needs or neglect them.  In this way, the baby
comes to rely on and cling to only those who meet his or her basic needs.  In contrast,
during the "care" stage (between 45 and 60 years old) a psychosocial task includes
making meaningful contributions to society and actively furthering the progress of
future generations.