Whilst 'Wage' and 'salary' are often used interchangeably, 'salary' refers in particular to payment associated with a position over a fixed period of time, such as per Week, per Month, or per Year. A manager or other person with oversight responsibilities (commonly referred to as a 'White-collar worker') would be more likely to draw a salary which does not vary with hours worked (also meaning that she would not receive Overtime pay). A labourer or 'Blue-collar worker' would take wages (usually paid weekly, biweekly, or monthly), based upon the actual hours worked.
From the point of view of running a Business, salary can also be viewed as the cost of acquiring human resources for running operations, and is then termed personnel expense or salary expense. In accounting, salaries are recorded in payroll accounts.
By the time of the Hebrew Book of Ezra (550 BC to 450 BC), accepting salt from a person was synonymous with drawing sustenance, taking pay, or being in that person's service. Depending on the translation of Ezra 4:14, the servants of King Artaxerxes I of Persia explain their loyalty variously as "because we are salted with the salt of the palace" or "because we have maintenance from the king" or "because we are responsible to the king."
Similarly, the Roman word salarium linked employment, salt and soldiers, but the exact link is unclear. The least common theory is that the word soldier itself comes from the Latin sal dare (to give salt). Alternatively, the Roman historian Pliny the Elder stated as an aside in his Natural History's discussion of sea water, that "[I]n Rome. . .the soldier's pay was originally salt and the word salary derives from it. . ." Plinius Naturalis Historia XXXI. Others note that soldier more likely derives from the Solidus (coin), with which soldiers were known to have been paid, and maintain instead that the salarium was either an allowance for the purchase of salt or the price of having soldiers conquer salt supplies and guard the Salt Roads (Via Salarium) that led to Rome. Regardless of the exact connection, the salarium paid to Roman soldiers has defined a form work-for-hire ever since in the Western world, and gave rise to such expressions as "being worth one's salt."
Yet within the Roman Empire or (later) medieval and pre-industrial Europe and its merchantile colonies, salaried employment appears to have been relatively rare and mostly limited to government service. More commonly, servitude either received no pay, as with Slavery, Serfdom, and indentured servitude, or received only fraction of what was produced, as with Sharecropping. Other common alternative models of work included self- or co-operative employment, as with Artisan guilds, or communal work and ownership, as with medieval universities and monasteries.
Even many of the jobs initially created by the Commercial Revolution in the years from 1520 to 1650 and later during Industrialisation in the 1700s and 1800s would not have been salaried, but, to the extent they were paid as employees, probably paid an hourly or daily Wage or paid per unit produced (also called Piece work). In corporations of this time, such as the several East India Companies many managers would have been compensated as owner-shareholders even as the current idea of the salaried manager began to emerge.
From 1870 to 1930, the Second Industrial Revolution gave rise to the modern business Corporation powered by railroads, electricity and the telegraph and telephone. This era saw the widespread emergence of a class of salaried executives and administrators who served the new, large-scale enterprises being created. New managerial jobs leant themselves to salaried employment, in part because the effort and output of "office work" were hard to measure hourly or piecewise, and in part because they did not necessarily draw compensation from Share ownership. As Japan rapidly industrialized in the 1900s, the idea of office work was novel enough that a new Japanese word (Salaryman), was coined to describe those who performed it, and their compensation.
In the 20th century, the rise of the Service economy made salaried employment even more common in developed countries, where the relative share of industrial production jobs declined, and the share of executive, administrative, computer, marketing, and creative jobs--all of which tended to be salaried--increased.
The idea of a salary continues to evolve as part of a system of all the combined rewards that employers offer to employees. Salary (also now known as fixed pay) is coming to be seen as part of a system which includes variable pay (such as bonuses, incentives, and commissions), benefits and perquisites (or perks), and various other tools which help employers link rewards to an employee's measured performance.
The six categories of salaried workers exempt from overtime provisions are: (1) Executive Employees, who hire, fire and direct others; (2) Administrative Employees, exercising discretion as part of office work; (3) Learned Professional Employees, such as doctors, lawyers, professors; (4) Creative Professional Employees in an artistic field; (5) Computer Employees, who must meet certain threshold tests; and (6) Outside Sales Employees, who must work away from an employer's place of business. Some of the 2004 exemption tests depend on being paid a weekly salary of greater than $455, even though no hourly minimum wage is required or maximum number of hours worked is established.