A comprehensive criminal background check involves collecting an applicant's personal information like name, aliases, addresses, education, and employment history. It also discloses any criminal records including past arrests, convictions, pending charges, and court decisions. Conducting criminal background checks is important for employers as it increases a company's success by ensuring they hire qualified employees, protects employees and customers from potential threats, and allows employers to make informed hiring decisions. The background check process involves a company evaluating applicant information from various criminal databases to provide details on criminal history and misconduct.