Final answer:
Pillars in Salt configuration files are used to manage sensitive and minion-specific variable data outside the state files, enhancing security and scalability in managing configurations across multiple minions.
Step-by-step explanation:
In Salt configuration files, pillars are a mechanism used to define and manage variable data that are specific to each minion. They allow for the storage of sensitive information such as passwords or keys, as well as configuration settings that are unique to each minion, outside of the state files for added security and flexibility. This helps in keeping the configurations organized and easier to maintain across different environments or minions. Pillars are extremely useful when dealing with hundreds or thousands of minions, as they provide a scalable way to manage data.