Self-esteem is
a. how we identify ourselves.
b. how we value ourselves.
c. how we present ourselves.
d. how we challenge ourselves.

Self-esteem is B. HOW WE VALUE OURSELVES.

It is how we think or perceive how others value us and what our value is to the world.

People with low self-esteem tend to be shy and easily hurt. They don't think much of themselves and oftentimes let themselves be used and abused by others. They tend to do the things others wanted them to do to gain acceptance and do not understand why others demean them.

People with high self-esteem exude confidence. They know who they are and what they are worth. They do not let others disrespect them and they show respect to others. People with high self-esteem are comfortable with themselves and also let others be comfortable with their own selves.  

Anxiety disorders, attention deficit hyperactivity disorder (adhd, add), and autism spectrum disorder (asd). (source: )