The ability to use instructions to prepare for upcoming events is a characteristic that humans uniquely developed. This cornerstone ability is evident in abundant prior studies, yet the exact role that instructions play in action control is unclear. We start with a survey of literature on instructions and action control, as well as the role that instructions play in action control. The review suggests that although the concept of task set based on task-relevant information is widely emphasized, the more critical concept is that of task space, which includes task-irrelevant information in a multidimensional representation and allows hierarchical switching between tasks. Within both concepts, stimulus-response relations are at the core, revealing the procedural nature of action control. Moreover, we use research on password generation to illustrate the application of task space to the area of cybersecurity and privacy. We argue that the task space framework captures the nature of the central processes of action control nested within a multi-dimensional representation from instructions, which can be extended to broader situations beyond laboratory settings.