Meaning, do not use software which requires a license. Why? This is why: the makers of it will screw you. See here.
Rather, invest your time in understanding open source alternatives. To quote from this article,
"It's not like they have really good software. It's just that it's widespread and it's commonly used," Gaertner said. "It's going to be a while, but eventually, we plan to get completely disengaged from those software vendors that participate in the BSA."