These refer to different contexts that a penetration test engagement can be approach. -Black Box This is where testing of a system or network is undertaken with no prior knowledge of its internal workings. From an assurance perspective, this means that testing is done without credentials or access to system documentation or source code. -Grey Box This is where testing of a system or network is undertaken with limited knowledge. From an assurance perspective, this means that login credentials may be provided to the system, but these may be limited to non-administrator level. Also, limited or no documentation would be available. -White box: This is testing of a system of network with full access to the entire system or network’s internal workings. This would typically include the tester having access to login credentials, design documents, source code, and stakeholder input.   Each of these approaches has their benefit, when it comes to gaining assurance of the security of your systems, depending upon the aims of the test. Dionach’s consultant will walk through the best testing approach for your specific project during the scoping phase.