We now understand work as energy transfer between systems through force applied over a distance, considering only the force component parallel to displacement. Work, measured in joules, increases kine...We now understand work as energy transfer between systems through force applied over a distance, considering only the force component parallel to displacement. Work, measured in joules, increases kinetic energy when force aligns with motion, as seen when pushing a box. Work also transfers energy to potential forms, such as gravitational potential energy in lifting objects or spring potential energy when stretching a spring. These examples illustrate how work drives energy changes in systems.