by default, the salary given to you by the company is pre-tax, that is to say, the salary includes a tax, and the employee pays a tax. The company only withholds the tax, and then pays this tax to the tax bureau. Here, the company only acts as a withholding agent, but the employee actually pays it.
another situation is that when the company talks with you about salary, it has been agreed that it is after-tax salary, that is to say, the company has paid the tax for you, but the individual actually pays the tax, but the tax here is borne by the company for you.