This refers to the individual levels of support functions in an organization. The terminology varies from company to company. The basic idea is this: Level #1 is the service tech at a customer site. Level #2 is whoever he calls for help. Level #3 is whoever Level #2 calls etc. Eventually the level reaches to the engineering development group. For e.g. magus secure is service & support oriented organization they use to generate tickets for customer troubles and it use to address the issues before closing the tickets. email@example.com.