He chose three letters
from among the Elementals
[in the Mystery of the three Mothers
Alef Mem Shin]
And he set them in His great Name
and with them, He sealed six Extremities.
…Eight: He sealed "west" and faced backward
and sealed it with ו ה י
— Sepher Yetzirah

Hod is Reason, the individual mind, systems of magick and science, the contact point of the Master. It is the appreciation of boundaries, classifying and categorizing, defining a place for everything and putting everything in its place. Where Netzach is active, telling us what we should like, Hod is receptive, elaborating on those feelings.

Above, I remark that Hod is appreciation of boundaries. It is: it's fussy and didactic, loving to categorize and classify, in opposition to Netzach, which is an emotional response. Author Terry Pratchett sums up the distinction very succinctly in his novel Lords and Ladies:

… It's all very well a potion calling for Love-in-idleness, but which of the thirty-seven common plants called by that name in various parts of the continent was actually meant?

The reason that Granny Weatherwax was a better witch than Magrat was that she knew that in witchcraft it didn't matter a damn which one it was, or even if it was a piece of grass.

The reason that Magrat was a better doctor than Granny was that she thought it did.