Tactical clothing refers to specialized apparel made to provide comfort and protection from the elements in dangerous situations, without hindering one’s ability to fulfill their tasks.
The difference between regular and tactical equipment, or clothing, is that tactical gear needs to have the requirements of the mission in mind first, and not only the comfort of the wearer.
Any type of garment, equipment, tools, or information that gives you an objective advantage when completing a task may be referred to as a tactical item.