Self-Efficacy is the belief which an individual has in one's own ability to achieve the goals & objective set by them. Self efficacy advocates that if a person puts in hardwork and it committed towards achieving the goals, they would end up being successful.
High or low self-efficacy will determine whether or not someone will choose or leave a challenging task. For example, self-efficacy of a person going to a gym is for how long that person will go to the gym.
Self efficacy can be explained by the following four theoretical approaches