Recruiting and onboarding are linked, but separate HR processes used for hiring new employees at a company.  Employee recruitment is the HR process of: identifying staffing needs, advertising open position(s), interviewing top candidates, and filling the position(s) with the right fit.
Employee onboarding is the process of introducing a newly hired employee to an organization through expectations, routine, and company culture. Designed to start a new employee off on the right foot, the onboarding process includes welcoming new employees, an overview of policies and expectations, various administrative tasks, and the start of training.