Answer:
As salaries are paid to workers by virtue of the work they perform, a factor that can be decisive for a salary increase is none other than a greater or better performance of the tasks that the worker performs.
On the other hand, wages can also rise if the country's minimum wage is raised, or if there is a situation of inflation that renders workers' wages useless over time.
And also, it may happen that the company that pays the worker's salary is in an exceptional situation that implies a salary improvement as a way of rewarding the performance of its workers.