Personal lives may be affected by all sorts of people and issues that erode self-esteem. Living in an abusive situation; being "put down" by people; being ridiculed (based on looks, size and age), all these things go to wearing away our feelings of worth, until those feelings and emotions get all tangled up, and we become what THEY want. Not what we want.
Self esteem is the value or worth that you place upon yourself.
It's as simple as that. You'll find countless books in the library; seminars advertised through magazines or television; numerous courses held by reputable (and not so reputable) facilitators, as well as one-to-one consultancy, all offering to help you gain self esteem.
But do you really need to spend thousands of dollars in order to be told what, in your heart of hearts, you already know?
And what do you know? That you're an intelligent, sensible, good and kind person. Well versed in whatever profession you work under - from being a homemaker and mother; to a carer; to a business woman; to a corporate director; to a health specialist; to a bus driver; to an excavator driver; to a pilot; to a student; to a person who makes sandwiches in the local coffee shop. It doesn't matter what you do, if you do it well.
Gaining satisfaction in what you do is a major part of having self-esteem.