https://www.tutor2u.net/psychology/reference/locus-of-control
Locus of Control (Rotter, 1966) is a construct that is said to be part of our personality. It is a continuum which runs from a strong external locus of control at one end of the continuum to a strong internal locus of control at the other end.
The basic idea of locus of control is that it describes the extent an individual feels in control of what happens to them and the extent to which they, as an individual, can affect their life.
A strong external locus of control describes when someone believes what happens to them is luck or fate and that they are not in control of their life; it is all due to external forces in their environment (for example other people).
A strong internal locus of control describes someone who believes they are in control of what happens to them
As an example imagine Danielle does not do well in an examination. She may say that it is because she didnt work hard enough, and should have revised more. This would mean she has an internal locus of control because she sees herself as to blame for the failure. Conversely, she could say that it was because the teacher couldnt teach and the exam was not fair. This would suggest that she has an external locus of control and sees external reasons for the failure.