What are "Clusters" in Unity?

Question

Unity

For the second day I have been struggling with an article on lighting off. Unity website, but my English can't understand it. Who can explain what clusters are and what they are eaten with?
Link to article

Answer 1

Do you really need to understand exactly what it is? then forgive you all the same to sit and pore over the translation.)
if in practice, then you can only influence the "density" of clusters in LightSettings.
In fact.. this is additional information about the scene. In these "clusters" the information spread out on hierarchy. with the help of it (but not only on its basis) the light is baked and in realtime a miscalculation occurs.
it is mentioned here, for example, that due to the hierarchy of information - by "clusters" you can determine which blocks on realtime require recalculation at the current moment, so as not to recalculate everything, once again loading the percent.
In general, as I mentioned earlier - in a unit, you can essentially just change the "density", and not create and specify something yourself (yes, this is usually not required - but here it must be taken into account that I come more from the experience of mobile development and namely baking, not realtime light)