Since we do a depth prepass, which is anyways needed for the lighting and which helps us to get rid of overdraw, one could already call our approach deferred. The idea behind tiled lighting is, that you split the screen into rectangles of the same size and generate a list for all lights visible in each of those rectangles. Then in the fragment shader used to render the scene, each fragment determines within which rectangle it is and uses the according list of lights for that, which is usually a lot less than the lights of the whole scene. An better approach is probably the so called clustered forward rendering, which also uses 3D boxes instead of 2D rectangles, by also taking the depth into account. I plan to change our system there, but did not yet get to experimenting with it.
I am gonna write a blog post about this somewhen in the future and will post some links for you somewhen later today or tomorrow.