Self-Concept and Self-Esteem
High self-esteem and a positive self-concept are important characteristics of children’s well-being. Researchers sometimes use these terms interchangeably, but there is a meaningful difference between the two.

Self-concept refers to the overarching conception of the self which is maintained by the individual. These are the more generalised descriptive beliefs that a child holds about him or herself as person.
Self-esteem refers to specific opinions and evaluations of the self. For example, a child may perceive that she is not merely a person but a good or bad person who is good or bad at some aspect of his or life.
(Butler & Gasson, 2005)
Self-efficacy
Albert Bandura is a Canadian-American psychologist who originated social cognitive theory. Bandura (1977) defines self-efficacy as the belief that one can master a situation and produce favourable outcomes - as such, he sees it as a critical factor in whether or not students achieve.
Self-efficacy is the belief that 'I can'; helplessness is the belief that 'I cannot'. Students with high self-efficacy endorse such statements as 'I know that I will be able to learn the material in this class' and 'I expect to be able to do well in this class'. Students with low self efficacy for learning may avoid many learning tasks, especially those that are challenging.