In a player's TNHC, the positions of the natal planets indicate their avatar's attributes. The particular expressions of these attributes are defined by the locus and the constellation the planets were projected.
In a player's THC, transiting planets drive influences onto the player's TNHC locus that they are crossing.
For example, the influences of the planet Venus are related to attributes of "aesthetic" or "harmony". When looking at the player's TNHC, Venus tells the statistics in the player's avatar for those attributes.
The fun lies in figuring out what to do — and sometimes where, how, or who to do — with all the attributes the player has been allocated.