Conventional current flow is a historical convention used to describe the movement of electric charge. According to this convention, the direction of conventional current is considered to be from positive to negative. In other words, it assumes that positive charges are the ones that move, even though in reality, it's the negatively charged electrons that move through a conductor, like a wire.
This convention was established before the true nature of electron flow was fully understood. Benjamin Franklin, who made significant contributions to understanding electricity, originally assigned the notion of positive and negative charges. Later, as the electron theory was developed, it was realized that electrons are the actual carriers of negative charge, moving in the opposite direction of conventional current.
Despite the actual flow of electrons being from negative to positive, the convention of using conventional current flow from positive to negative is still widely used in circuit diagrams and electrical engineering because it simplifies calculations and communication.