L1 or level 1 support includes interacting with the customers, understanding their problems and then creating a ‘ticket’ against it. A ‘ticket’, also referred to as ‘incident’ is then routed to the L2 or level 2 support. Sometimes the request/grievance raised by the customer is minor and can be solved by the L1 support as well.
L2 or level 2 support manages the tickets which are routed to them by the L1. These tickets/incidents may require some technical knowledge which the L1 team does not possess, in this scenario the L2 support takes over.
L3 is the last line of support and usually comprises of a developer team which addresses the technical issues. Sometimes the issues reported by customers cannot be solved by L1 & L2.In that case, the L3 team analyses the issue and fixes it. The issues which the L3 team gets involves code/development related fixes.