My coworker gives me a nod, what does it means?

[Anonymous]

I think he smiles but I don't remember

[molonski2]

Just a gesture of greeting " good morning " " hello " " how are you " , I do it all the time , I think its a nice way to acknowledge.

[AngryCarl2]

There is insufficient data for a meaningful answer.

[spartan55]

It's an unspoken greeting.

[BrookeS]

It means hi or hello

[TheAfrikan]

A way of recognition I guess.