An employer may have a number of separate payrolls, all of which fall within its authority. For example, there might be an executive payroll, a monthly payroll and a weekly payroll all forming part of one employer.
There may be more than one employer in one database, although this will probably not be the norm. However, a number of associated institutions, each with its own set of payrolls, may conveniently reside on one database. The advantage of such an arrangement is that each database can be backed up and restored without the danger of corrupting data for other employers.